WWW: Upgrade Documentation URLs from /latest to /stable

[mjherzog]

In general we want to reference the '/stable/' version of an RTD documentation page for an AboutCode project in preference to '/latest/'.
The changes we need to make for now are:

Project	Current	Change to
aboutcode-toolkit	https://aboutcode.readthedocs.io/projects/aboutcode-toolkit/en/latest/	https://aboutcode.readthedocs.io/projects/aboutcode-toolkit/en/stable/
ai-gen-code-search	https://ai-gen-code-search.readthedocs.io/en/latest/	https://ai-gen-code-search.readthedocs.io/en/stable/
dejacode	https://dejacode.readthedocs.io/en/latest/	https://dejacode.readthedocs.io/en/stable/
federatedcode	https://federatedcode.readthedocs.io/en/latest/	https://federatedcode.readthedocs.io/en/stable/
purldb	https://aboutcode.readthedocs.io/projects/PURLdb/en/latest/	https://github.com/aboutcode-org/purldb/blob/main/README.rst
scancode-workbench	https://scancode-workbench.readthedocs.io/	https://scancode-workbench.readthedocs.io/latest
vulnerablecode	https://vulnerablecode.readthedocs.io/en/latest/	https://vulnerablecode.readthedocs.io/en/stable/

[johnmhoran]

@mjherzog Updated and deployed to GH Pages.

[mjherzog]

Looks good