Docs update

[dmunozv04]

Proposed changes

This PR updates mkdocs, and creates a readthedocs config file to fix doc builds, since they're failing right now. It also fixes a few links that leaded to a 404 before.

Types of changes

What types of changes does your code introduce to the project: Put an x in the boxes that apply

• [x] Bugfix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code.

• [x] I have read the CONTRIBUTING doc
• [x] I have signed the CLA
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] I have added necessary documentation (if appropriate)
• [ ] Any dependent changes have been merged and published in downstream modules

Further comments

[coveralls]

coverage: 88.21%. remained the same when pulling 04018f9f49160f3350a05b2daca71264593323cc on dmunozv04:docs-update into 2a25766282456578de3663734a69b0281ed88bb8 on Wirecloud:develop.