Fix typos and update outdated link in documentation

[Marcofann]

This PR addresses minor typos in the Contributor's Guide across multiple versions and updates an outdated link in the README.md. These changes enhance readability and maintain consistency in the documentation.

Changes made:

1. Fixed grammar issue:

   • Changed "a ecosystem" to "an ecosystem" in the Contributor's Guide across all the following files:
     • docs/docs/contributor-guide.md
     • docs/versioned_docs/version-1.10.1/contributor-guide.md
     • docs/versioned_docs/version-2.8.0/contributor-guide.md
     • docs/versioned_docs/version-3.0.0/contributor-guide.md
     • docs/versioned_docs/version-3.1.0/contributor-guide.md
     • docs/versioned_docs/version-3.2.0/contributor-guide.md
     • docs/versioned_docs/version-3.3.0/contributor-guide.md

2. Updated link in README.md:

   • Replaced the outdated link https://dev.ingonyama.com/icicle/introduction with the correct link https://dev.ingonyama.com.