Clean up of documentation build (#6620)

[ricklarsen]

FORWARD PORT of #6620

What does this PR do?

removes warnings and errors from documentation build:

• normalize section headings
• fixes incomplete table markup
• fixes typoes typos

Reviewers

@shaundmorris
@sgalla
@rececoffin
@jaymcnallie

Select relevant component teams:

@codice/docs

How should this be tested?

build normally. Log output reduced, content renders

Checklist:

• Documentation Updated
• Update / Add Threat Dragon models
• Update / Add Unit Tests
• Update / Add Integration Tests

Notes on Review Process

Please see Notes on Review Process for further guidance on requirements for merging and abbreviated reviews.

Review Comment Legend:

• ✏️ (Pencil) This comment is a nitpick or style suggestion, no action required for approval. This comment should provide a suggestion either as an in line code snippet or a gist.
• ❓ (Question Mark) This comment is to gain a clearer understanding of design or code choices, clarification is required but action may not be necessary for approval.
• ❗ (Exclamation Mark) This comment is critical and requires clarification or action before approval.

[ricklarsen]

build now

[cxddfbot]

Internal build has been started, your results will be available at build completion.

[cxddfbot]

Build SUCCESS See the job results in legacy Jenkins UI or in Blue Ocean UI.