adding contributing guideline (#259)

* adding contributing guideline 

* adding further dev support information

CONTRIBUTING.md

@@ -0,0 +1,78 @@
+# Contributing
+
+The OQS core team welcomes all proposals to improve this project. This may take 
+the form of [a discussion](https://github.com/open-quantum-safe/oqs-provider/discussions)
+for input or feedback, possible bug reports or feature requests via [issues](https://github.com/open-quantum-safe/oqs-provider/issues)
+as well as new code and documentation via a [pull request (PR)](https://github.com/open-quantum-safe/oqs-provider/pulls).
+
+## Review and Feedback
+
+We aim to provide timely feedback to any input. If you are uncertain as to whether
+a particular contribution is welcome, needed or timely, please first open an [issue](https://github.com/open-quantum-safe/oqs-provider/issues)
+particularly in case of possible bugs or new feature requests or create a
+[discussion](https://github.com/open-quantum-safe/oqs-provider/discussions).
+
+## Pull requests
+
+Pull requests should clearly state their purpose, possibly referencing an existing
+[issue](https://github.com/open-quantum-safe/oqs-provider/issues) when resolving it.
+
+All PRs should move to "Ready for Review" stage only if all CI tests pass (are green).
+
+The OQS core team is happy to provide feedback also to Draft PRs in order to improve
+them before the final "Review" stage.
+
+### Coding style
+
+This project has adopted the [OpenSSL coding style](https://www.openssl.org/policies/technical/coding-style.html).
+To check adherence of any new code to this, it therefore is highly recommended to
+run the following command in the project main directory prior to finishing a PR:
+
+    find oqsprov -type f -and '(' -name '*.h' -or -name '*.c' -or -name '*.inc' ')' | xargs clang-format --dry-run --Werror
+
+### Running CI locally
+
+#### CircleCI
+
+If encountering CI errors in CircleCI, it may be helpful to execute the test jobs
+locally to debug. This can be facilitated by executing the command
+
+   circleci local execute --job some-test-job
+
+assuming "some-test-job" is the name of the test to be executed and the CircleCI
+[command line tools have been installed](https://circleci.com/docs/local-cli).
+
+#### Github CI
+
+[Act](https://github.com/nektos/act) is a tool facilitating local execution of
+github CI jobs. When executed in the main `oqsprovider` directory, 
+
+    act -l Displays all github CI jobs
+    act -j some-job Executes "some-job"
+
+When installing `act` as a github extension, prefix the commands with `gh `.
+
+### New features
+
+Any PR introducing a new feature is expected to contain a test of this feature
+and this test should be part of the CI pipeline, preferably using Github CI.
+
+## Background knowledge
+
+New contributors are recommended to first check out documentation of the 
+[OpenSSL provider concept](https://www.openssl.org/docs/man3.0/man7/provider.html)
+as well as the baseline API of [liboqs](https://github.com/open-quantum-safe/liboqs)
+which are the two core foundations for this project.
+
+## Failsafe
+
+If you feel your contribution is not getting proper attention, please be sure to
+add a tag to one or more of our [most active contributors](https://github.com/open-quantum-safe/oqs-provider/graphs/contributors).
+
+## Issues to start working on
+
+If you feel like contributing but don't know what specific topic to work on,
+please check the [open issues tagged "good first issue" or "help wanted"](https://github.com/open-quantum-safe/oqs-provider/issues).
+
+
+

DEVELOPMENT.md

@@ -0,0 +1,58 @@
+# Development guidelines
+
+## Basics
+
+Every developer has their own coding style and diversity in general is good and welcome.
+
+We nevertheless do try to follow some basic goals in this project:
+
+- All pieces should be readable / understandable without having to comprehend all parts first.
+- Therefore, comments (incl. cross references where sensible) are encouraged.
+- For syntactical legibility the project adopted the [OpenSSL coding convention](https://www.openssl.org/policies/technical/coding-style.html)
+- Tooling exists to validate the coding convention: Simply execute `clang-format --dry-run --Werror file-to-test`
+- Platform-specific code should be avoided to the greatest extent possible as the project aims to run correctly at least on Linux, MacOS and Windows (x64 and aarch64 architectures).
+
+## Generated code
+
+Significant parts of the code are generated via the script `oqs-template/generate.py`.
+This script serves to import a specific version of [liboqs](https://github.com/open-quantum-safe/liboqs)
+into `oqsprovider`. Most notably the control file `oqs-template/generate.yml` has to be
+in sync with the specific `liboqs` version: algorithm IDs, e.g., signature algorithm
+OIDs need to be aligned with the specific algorithm code version.
+Therefore, no code within the generator brackets must be changed:
+
+```
+///// OQS_TEMPLATE_FRAGMENT_..._START
+...
+///// OQS_TEMPLATE_FRAGMENT_..._END
+```
+
+If such code changes are required they have to be implemented in the generator code
+fragments located in the `oqs-template` directory.
+
+During normal code development it is very unlikely any of these files need to be touched.
+
+## Plain build
+
+If the prerequisites for `oqsprovider` are met on a development machine, i.e.
+presence of `liboqs` and `openssl` (v.3) the build can simply be executed by
+running `scripts/fullbuild.sh`. Various parameters exist and are documented
+in the script to adapt to a specific build environment and in [the documentation](CONFIGURE.md#convenience-build-script-options).
+The script can also be used to build a specific `openssl` and a specific `liboqs`
+version as well as debug versions of all components.
+
+## Plain test
+
+All tests meant for local feature testing are integrated/made available for
+execution in the script `scripts/runtest.sh`. PRs should only be considered
+if all tests pass locally as the CI system uses them too.
+
+## Debugging
+
+Project-specific debugging facilities are documented in [the wiki](https://github.com/open-quantum-safe/oqs-provider/wiki/Debugging).
+
+For "classic" `gdb` style debugging, be certain to set "-DCMAKE_BUILD_TYPE=Debug"
+when building `oqsprovider` and `-d` when configuring `openssl` (see
+"scripts/fullbuild.sh" for further information where best to do this).
+
+