docs: migrate FlexRIC documentation and resources

[sgarg00]

This PR migrates the FlexRIC documentation and resources to the duranta-projects/docs repository.

Documentation

• README.md is taken from:
  https://gitlab.eurecom.fr/mosaic5g/flexric/-/blob/docs-github-migration/README.md?ref_type=heads
• As discussed, the current README.md in the FlexRIC repository will contain the relevant documentation links, license information, and related details.

Wikis and Resources

The wiki content and resources were migrated from:

git clone https://gitlab.eurecom.fr/mosaic5g/flexric.wiki.git

Changes

Only minor changes were made during the migration:

• Typo fixes
• Formatting fixes
• File name fixes
• Resource name fixes

Reviewer

• Verify that file names and resource names are okay.
• Documentation content is okay.
• Review the migrated documentation and resources.

[teodora-vladic]

The wiki content and resources were migrated from:

git clone https://gitlab.eurecom.fr/mosaic5g/flexric.wiki.git

Please elaborate in the commit message that the files names are modified, i.e.:
<before.md> -> <after.md>

And please split the commit for better review and visibility (e.g. move main README, move wiki, rename wiki tutorials,...)

[sgarg00]

As per today's CI meeting's discussion, we now are not sure if we want to maintain a separate duranta-project/docs repository. So, will resume this PR once the maintainer's come to a conclusion.