Add patched sphinx_rtd_theme

There must be a cleaner way to do this... Currently, this theme is built
with:

--- a/sass/_theme_layout.sass
+++ b/sass/_theme_layout.sass
@@ -292,7 +292,7 @@
 .wy-nav-content
   padding: $gutter $gutter * 2
   height: 100%
-  max-width: 800px
+  max-width: 1000px
   margin: auto

 .wy-body-mask
@@ -354,13 +354,6 @@ footer
       height: 100%
       overflow: hidden

-+media($desktop-wider)
-  .wy-nav-content-wrap
-    background: rgba(0,0,0,.05)
-  .wy-nav-content
-    margin: 0
-    background: $section-background-color
-
 @media print
   .rst-versions, footer, .wy-nav-side
     display: none

and this on bower_components/wyrm/sass/wyrm_core/_wy_variables.sass

- $base-font-size:                      16px !default
+ $base-font-size:                      18px !default
  $base-font-family:                    "Helvetica Neue", Arial, sans-serif !default
  $base-font-family-bold:               bold
- $base-line-height:                    24px !default
+ $base-line-height:                    27px !default

conf.py

@@ -108,7 +108,7 @@ html_theme = "sphinx_rtd_theme"
 #html_theme_options = {}
 
 # Add any paths that contain custom themes here, relative to this directory.
-#html_theme_path = []
+html_theme_path = ['_themes']
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".