Remove `$` leaders from examples of editing text in a file

not everything that is indented is a commandline example

Closes #6591

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Merge pull request #6611 from SvenDowideit/remove-spurious-dollar-signs

Remove `$` leaders from examples of editing text in a file