docs: address some text issues with css/theme support

Fix:
- overriden ->overridden
- some whitespace issues introduced at the css/theme
  Makefile help.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/b0b166025019f7cc4f122bd789c79ba28cc2d29d.1639212812.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/Makefile

@@ -159,8 +159,8 @@ dochelp:
 	@echo  '  make SPHINX_CONF={conf-file} [target] use *additional* sphinx-build'
 	@echo  '  configuration. This is e.g. useful to build with nit-picking config.'
 	@echo
-	@echo '   make DOCS_THEME={sphinx-theme} selects a different Sphinx theme.'
+	@echo  '  make DOCS_THEME={sphinx-theme} selects a different Sphinx theme.'
 	@echo
-	@echo '   make DOCS_CSS={a .css file} adds a DOCS_CSS override file for html/epub output.'
+	@echo  '  make DOCS_CSS={a .css file} adds a DOCS_CSS override file for html/epub output.'
 	@echo
 	@echo  '  Default location for the generated documents is Documentation/output'

Documentation/doc-guide/sphinx.rst

@@ -147,7 +147,7 @@ By default, the build will try to use the Read the Docs sphinx theme:
 
 If the theme is not available, it will fall-back to the classic one.
 
-The Sphinx theme can be overriden by using the ``DOCS_THEME`` make variable.
+The Sphinx theme can be overridden by using the ``DOCS_THEME`` make variable.
 
 To remove the generated documentation, run ``make cleandocs``.