Update TF-M CI job description

This patch updates TF-M CI job description to introduce the detailed
workflows of different jobs. And add instruction on how to read CI job
logs and artifacts.

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: Ia10ce1df9df5178fbd4e39276749f5917a051257
16 files changed
tree: ea5d311cd8810d872d6b3b0c722885964f6ff570
  1. docs/
  2. .gitreview
  3. mkdocs.yml
  4. requirements.txt