projects: wethlink: Added readme document

[jvelasc2]

projects: wethlink: Added readme document

PR Type

• Bug fix (change that fixes an issue)
• New feature (change that adds new functionality)
• Breaking change (has dependencies in other repos or will cause CI to fail)

PR Checklist

• I have followed the Coding style guidelines
• I have complied with the Submission Checklist
• I have performed a self-review of the changes
• I have commented my code, at least hard-to-understand parts
• I have build all projects affected by the changes in this PR
• I have tested in hardware affected projects, at the relevant boards
• I have signed off all commits from this PR
• I have updated the documentation (wiki pages, ReadMe etc), if applies

[buha]

this one's a bit more particular than others, it has a proper doc on the wiki and that needs to be ported here:
https://wiki.analog.com/resources/eval/user-guides/admv96s-wgbe-ek1

if you search admv96s in wiki, you'll get 4 results, all of them need to be imported as sphinx doc, with the attachments