docs: add getting involved section to contribution guidelines (#317)

Author: nicklasl

CONTRIBUTING.md

@@ -1,18 +1,29 @@
-## Contributing
+# Contributing
 
-### Commit and PR linting
+## Getting Involved
+
+We welcome contributions and are happy to discuss ideas, answer questions, and help you get started.
+
+**Before opening a pull request**, please open an issue or start a discussion with the maintainers. This helps us:
+- Ensure the change aligns with the project's direction
+- Avoid duplicate or conflicting work
+- Provide guidance on implementation approach
+
+We're friendly and responsive—don't hesitate to reach out!
+
+## Commit and PR linting
 We require pull request titles to follow the Conventional Commits specification and we also encourage individual commits to adher to that.
 
 We use "squash merge" and any merge PR title will show up in the changelog based on the title.
 
-### Testing
+## Testing
 We ask you to write well covered unit tests with your changes. To run tests:
 ```shell
 mvn verify
 ```
 As part of the CI pipeline, tests will run on java version 11 and 17.
 
-### Formatting
+## Formatting
 
 Please make sure you format your code according to [google-java-format](https://github.com/google/google-java-format) before making a PR. 
 There are CI checks using [fmt](https://github.com/spotify/fmt-maven-plugin) that will fail otherwise.
@@ -22,19 +33,19 @@ You can use `fmt` to format your code using:
 mvn com.spotify.fmt:fmt-maven-plugin:format
 ```
 
-### Signing
+## Signing
 Maven is configured to sign the generated artifacts using GPG. This is a security measure required for uploading to Maven Central.
 
 Signing passphrases are securely stored in Github's CI, but the signing operation is not needed when developing locally and can always
 be skipped via the argument `-Dgpg.skip`
 
-### Releasing
+## Releasing
 Github Actions are set up that are able to:
 - Create automated PRs to manage new Github tags/releases
 - Manage versioning automatically (including the `pom.xml` file)
 - Upload the generated artifacts to Maven Central **Staging**
 
 In order to promote an uploaded version from **Staging** to **Release** (hence making it openly available on [Maven Central Search](https://central.sonatype.com/)) a user with the right credentials must login into the the [Sonatype UI](https://oss.sonatype.org/#welcome) and perform the release process manually.
 
-#### After realeasing
+### After realeasing
 After a release PR is merged, the main branch will stay at the release version (non-snapshot) until updated. Release please will create a PR ([example](https://github.com/spotify/confidence-sdk-java/pull/55)) that does this "snapshot bump". The recommendation is to merge that PR directly when possible.