Merge pull request #412 from sbesson/rebased/develop/theme_cleanup

Remove plonematch theme from OME documentation (rebased onto develop)
Use current usage output in CLI importer arguments
Additional importer-cli configuration notes
Give more details in importer.config notes
Remove unnecessary CLI usage comments
Correct typo + use :file: ReST role
Use suggested wording + some reformating
Harmonize CLI arguments (suppress '=' operators)
Harmonize CLI arguments (right-align options text)
Correct spelling ('overridden')
Add missing full stops
Format file/directory names as literals
Americanize spelling (utilise vs utilize)
Sync DropBox and CLI import arguments
Format filenames using the :file: syntax
Add TypeDescription to the modulo page, see #10397

Also make the .ome.tiff extensions consistent.
merge develop -D org -I include -E exclude: PR 369 (Cpp: Correct content and markup)
merge develop -D org -I include -E exclude: PR 404 (Updating Download screenshots for Version 5 (FS))
merge develop -D org -I include -E exclude: PR 413 (Rebased/develop/doc patch importer cli dev 4 4)
merge develop -D org -I include -E exclude: PR 414 (Rebased/develop/doc patch dropbox dev 4 4)