Docker/Readme: codestyle cleanup (9af6bf1 follow-up) (#25864)

* Docker/Readme: codestyle cleanup

Changes proposed:
- Simplify MD back tick usage in stand-alone horizontal strings.
- Sentence grammar improvements/adjustments (might->may etc.)
- Punctuation: Add a period dot at the end of proper sentences.
- Punctuation: Add Oxford commas for natural readability.
- Punctuation: Add colon at the end of sentence introducing command examples.
- Reduce indentation level for bullet point annotation from second level to first level.
- Spell Linux with a capital L (proper noun, from "Linus + UNIX").
- UNIX is a proper noun with all its letters in uppercase.
- Remove a stray double quote character from the start of a command.
- Replace HTML entity . with its ASCII representation, a period dot.

Whitespace changes:
- add editorial blank line below H1 (page title) and H2 headings
- add editorial blank line below MD code block fences (codestyle)

* Lowercase 'pch' job name

- "PCH" -> pch

* Revert HTML entity change in README dot md

- Revert README.md to its original `README.md` spelling to avoid coding issues.

* Update contrib/Docker/README.md

Co-authored-by: Trond B. Krokli <38162891+illfated@users.noreply.github.com>

Co-authored-by: Giacomo Pozzoni <giacomopoz@gmail.com>
(cherry picked from commit 3a61fe3c31b3fc61d3b881196319ccd96d69c7e4)

0 files changed, 0 insertions, 0 deletions