feature detect for FNM_EXTGLOB for older Ruby. Fixes #15053
Keep method's description/documentation consistent [ci skip]
Merge pull request #15054 from mechanicles/documentation-consistency

Keep method's description/documentation consistent [ci skip]
Change Gemfile’s double quotes in plugin generator

Since the generated application’s Gemfile is using single quotation marks, it
seems fair to use it on plugin’s Gemfile as well.
Merge pull request #15056 from josemarluedke/single-quotes-on-plugin-gemfile

Change Gemfile’s double quotation marks in plugin generator
docs, fix typo in docs added by ed56e596a04673. [ci skip]