docs: RTD theme upgraded

docs/CMakeLists.txt

@@ -43,8 +43,6 @@ set(unitsSphinxDocs
     "${CMAKE_CURRENT_SOURCE_DIR}/_static/img/downcast_2.png"
     "${CMAKE_CURRENT_SOURCE_DIR}/_static/img/units.png"
 
-    "${CMAKE_CURRENT_SOURCE_DIR}/_themes/sphinx_rtd_theme.zip"
-
     "${CMAKE_CURRENT_SOURCE_DIR}/CHANGELOG.md"
 
     "${CMAKE_CURRENT_SOURCE_DIR}/design.rst"

docs/conf.py

@@ -10,6 +10,7 @@
 """
 
 import re
+import sphinx_rtd_theme
 
 from pygments.lexer import RegexLexer, include, bygroups, using, \
     this, inherit, default, words
@@ -272,6 +273,7 @@ extensions = [
     'sphinx.ext.autosectionlabel',
     'sphinx.ext.githubpages',
     'sphinx.ext.graphviz',
+    'sphinx_rtd_theme',
     'recommonmark',
     'breathe'
 ]
@@ -323,11 +325,6 @@ cpp_index_common_prefix = ['units::']
 
 # -- Options for HTML output -------------------------------------------------
 
-# A list of paths that contain custom themes, either as subdirectories or as
-# zip files. Relative paths are taken as relative to the configuration directory.
-
-html_theme_path = ["_themes", ]
-
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 html_theme = 'sphinx_rtd_theme'

docs/requirements.txt

@@ -1,3 +1,4 @@
 sphinx>=2.4.4
+sphinx_rtd_theme
 recommonmark
 breathe>=4.14.1