[Starlingx-discuss] Add StarlingX docs to our manifest

[Scott Little]

Goal:

    Designers and testers need a copy of the documentation that is 
contemporary with the code being worked on or tested.

Assumptions:

    A git clone of starlingx/docs can be read as is, or can be easily 
transformed into a readable form.

Solution:

1) Add starlingx/docs to the repo manifest.

     - When a designer pulls new software, he/she also pulls new 
documentation at the same time.
     - If a designer elects to work with a snapshot of the code for an 
extended period without pulling software updates, he/she continues to 
have access to the documentation of the same vintage.
     - This facilitates concurrent update of software and docs.
     - Does the designer need to read raw rst, or can he transform it to 
something he can use a web browser on to facilitate navigation.

2a) CENGN build publishes a versioned link to docs that matches the build.

     - In raw rst form, it might look like 
https://review.opendev.org/gitweb?p=starlingx/docs.git;a=tree;hb=<sha>
     - Can we publish a similar link to docs.starlingx.io to get a 
formatted web page matching a specific sha?

2b) Can and should CENGN run the software that transforms the the docs 
git into web form?

     - Assumes internal links can be version qualified, or must be relative.
     - Feels like CENGN would be displacing docs.starlingx.io