pages*: make help and version commands comply with the style guide (#12107)

* pages*: use generic word for help

* git: add newline to the end

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

* pages*: make help and version commands comply with the style guide

* java: fix Java name

---------

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

pages/common/gh-completion.md

@@ -3,10 +3,6 @@
 > Generate shell completion scripts for GitHub CLI commands.
 > More information: <https://cli.github.com/manual/gh_completion>.
 
-- Display the subcommand help:
-
-`gh completion`
-
 - Print a completion script:
 
 `gh completion --shell {{bash|zsh|fish|powershell}}`
@@ -18,3 +14,7 @@
 - Append the `gh` completion script to `~/.zshrc`:
 
 `gh completion --shell {{zsh}} >> {{~/.zshrc}}`
+
+- Display the subcommand help:
+
+`gh completion`