Fix format, rendering, typos, syntax, content in manuals.

[vkucera]

• Fix Markdown syntax.
• Fix code rendering.
• Sync content between manual and manual-premium. (Attempted to take the more recent pieces from each.)
  • I assume the premium version is supposed to be a trivial extension of the normal version, which should probably be automated by simply appending the extra section and changing the title.
• Fix capitalisation of headings.
• Fix capitalisation of abbreviations: XML, HTML, JSON, GCC.
• Fix capitalisation of Cppcheck in prose.
• Remove trailing spaces.
• Fix missing commas after "If", "To".
• Other English syntax fixes.
• "etc" -> "etc."
• "...." -> "..."

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[danmar]

hmm this version is not correct. next premium version will be 26.x.0 . I don't know what "x" will be. I don't feel that we want to mantain this manually and skipping the subtitle seems easier..

[vkucera]

OK. What about the non-premium version?

[lekanmatto-ship-it]

• Fix Markdown syntax.

• Fix code rendering.

• Sync content between manual and manual-premium. (Attempted to take the more recent pieces from each.)

  • I assume the premium version is supposed to be a trivial extension of the normal version, which should probably be automated by simply appending the extra section and changing the title.

• Fix capitalisation of headings.

• Fix capitalisation of abbreviations: XML, HTML, JSON, GCC.

• Fix capitalisation of Cppcheck in prose.

• Remove trailing spaces.

• Fix missing commas after "If", "To".

• Other English syntax fixes.

• "etc" -> "etc."

• "...." -> "..."

Hello