Changes suggested by the Docs Squad:
* Modify rule s2178: Update rule description
- formalize word selection to clarify the description
* Modify rule S2551: capitalize `String`
- follow the capitalization of a proper noun, in accordance with the referenced link
* Modify rule S3923: improve word choice
* Modify rule S2551: capitalize String
- `String` is used as a VB `object` in this example.
- A new PR will be issued to make a more substantial improvement
* Modify rule S1110: Update rule description
Improve grammar and sentence structure.
* Modify rule S3603: Update rule description
Improve grammar in the sentence structure.
* Modify rule S3449: Update rule description
Clarify the sentence structure with minor word changes.
* Modify rule S3449: correct word in description
Correct spelling mistakes in two instances of one word.
When an include is not surrounded by empty lines, its content is inlined
on the same line as the adjacent content. That can lead to broken tags
and other display issues.
This PR fixes all such includes and introduces a validation step that
forbids introducing the same problem again.
Inline adoc files when they are included exactly once.
Also fix language tags because this inlining gives us better information
on what language the code is written in.
