Add "How to Run a Tessera Log (MySQL)" (#163)

* Add "How to Run a Tessera Log (MySQL)"

* Add warning message about the example is not fit for production use

cmd/example-mysql/README.md

@@ -0,0 +1,49 @@
+# How to Run a Tessera Log (MySQL)
+
+> [!WARNING]
+> - This is an example and is not fit for production use, but demonstrates a way of using the Tessera Log with MySQL storage backend.
+> - This example is built on the [tlog tiles API](https://c2sp.org/tlog-tiles) for read endpoints and exposes a /add endpoint that allows any POSTed data to be added to the log.
+
+The tessera log with the MySQL storage implementation can be started with either Docker Compose or manual `go run`.
+
+Note that all the commands are executed at the root directory of this repository.
+
+## Docker Compose
+
+### Prerequisites
+
+- [Docker Compose](https://docs.docker.com/compose/install/)
+
+### Starting
+
+```sh
+docker compose -f ./cmd/example-mysql/docker/compose.yaml up
+```
+
+Add `-d` if you want to run the log in detached mode.
+
+### Stopping
+
+```sh
+docker compose -f ./cmd/example-mysql/docker/compose.yaml down
+```
+
+## Manual 
+
+### Prerequisites
+
+Assume you have the MySQL database ready. An alternative way is to run a MySQL database via [Docker](https://docs.docker.com/engine/install/).
+
+```sh
+docker run --name test-mysql -p 3306:3306 -e MYSQL_ROOT_PASSWORD=root -e MYSQL_DATABASE=test_tessera -d mysql
+```
+
+### Starting
+
+```sh
+go run ./cmd/example-mysql --mysql_uri="root:root@tcp(localhost:3306)/test_tessera" --init_schema_path="./storage/mysql/schema.sql" --private_key_path="./cmd/example-mysql/docker/testdata/key" --public_key_path="./cmd/example-mysql/docker/testdata/key.pub"
+```
+
+### Stopping
+
+<kbd>Ctrl</kbd> <kbd>C</kbd>