Inconsistencies between CONTRIBUTING.md and the Guide's pages on contributing

[orisdorch]

https://docs.symbol.dev/contribute/contributing.html contains far clearer and more detailed instructions on contributing to the guide than CONTRIBUTING.md in the Symbol-docs root directory. CONTRIBUTING.md should be updated to reflect this - either by linking to the guide's page(s) on contributing to the guide, or updating CONTRIBUTING.md to include the same contents.

New contributors who find CONTRIBUTING.md will likely be unaware of the more refined set of contribution instructions/guidelines more deeply nested in the repository.

[orisdorch]

The instructions on https://docs.symbol.dev/guidelines/writing-a-guide.html don't include instructions to create a .po file, which is required for translation. These instructions also seem to be missing from https://docs.symbol.dev/guidelines/translating-the-documentation.html - so it seems there is a gap in the workflow set out by the guide.

This gap is at least partially bridged by the instructions in under the heading "Updating translations".

Ideally the guide should be updated to cover the creation of .po files in addition to any changes made to CONTRIBUTING.md .