Doc: Update env TOML -> RST improvements

[tomschr]

Changes to the TOML -> RST parser:

[github-actions]

Coverage Report

For commit c982654

Click to expand Coverage Report

  Name                                           Stmts   Miss Branch BrPart  Cover
  --------------------------------------------------------------------------------
+ src/docbuild/cli/cmd_check/process.py             58      0     22      1  98.8%
+ src/docbuild/models/manifest.py                  111      1     12      1  98.4%
+ src/docbuild/utils/pidlock.py                     79      1     14      1  97.8%
+ src/docbuild/cli/cmd_config/list.py               26      0      8      1  97.1%
+ src/docbuild/cli/cmd_validate/process.py         178      5     52      4  96.1%
+ src/docbuild/cli/callback.py                      35      0     10      2  95.6%
+ src/docbuild/utils/concurrency.py                 69      3     18      1  95.4%
+ src/docbuild/cli/cmd_cli.py                      110      3     16      3  95.2%
- src/docbuild/config/xml/stitch.py                 47      5     12      0  88.1%
- src/docbuild/cli/cmd_metadata/metaprocess.py     215     26     66     13  82.6%
- src/docbuild/cli/cmd_config/validate.py           21      2     12      3  78.8%
- src/docbuild/cli/cmd_check/__init__.py            18      5      2      0  65.0%
- src/docbuild/cli/cmd_build/__init__.py            13      5      0      0  61.5%
- src/docbuild/cli/cmd_metadata/__init__.py         27     10      2      0  58.6%
  --------------------------------------------------------------------------------
+ TOTAL                                           3154     66    770     30  97.1%
  
  50 files skipped due to complete coverage.