docs(contributing): 📝 Update community branch references

Updated the contributing guidelines to reflect the correct branch name for community contributions. The main branch for this fork is now referred to as `main-community`, ensuring clarity for contributors on where to push their changes.

This change helps maintain accurate documentation and supports a smoother contribution process.

Author: maicol07

CONTRIBUTING.md

@@ -50,8 +50,8 @@ get community feedback.
 
 ### Material Web Community guidelines
 We have created this project to be a community-driven effort to maintain and improve the M3 web components. We encourage contributions from anyone who wants to help.
-Every change must be pushed to a separate branch (checked out from the `main` branch), and we will review it before merging it into the `main-fork` branch (the main branch of this fork). This way, we can keep track of all the changes made by the community and ensure that they are compatible with the original repo.
-Then that braanch can be used to create a PR to the original repo (M3 web) if needed and `main-fork` can be used to publish new versions of the components to npm faster.
+Every change must be pushed to a separate branch (checked out from the `main` branch), and we will review it before merging it into the `main-community` branch (the main branch of this fork). This way, we can keep track of all the changes made by the community and ensure that they are compatible with the original repo.
+Then that braanch can be used to create a PR to the original repo (M3 web) if needed and `main-community` can be used to publish new versions of the components to npm faster.
 This way we are covered in both cases:
 - M3 web (original repo) will be maintained
 - M3 web will be discontinued/deprecated