chore: Allow building from venv; bump version (#24)

Also had to update the test fixtures because mkdocs, bootstrap, whatever it may be have changed, so the sites end up slightly different.

Reviewed-on: #24
Co-authored-by: Glen Whitney <glen@studioinfinity.org>
Co-committed-by: Glen Whitney <glen@studioinfinity.org>

tests/fixtures/theme-modification/refsite/css/theme_extra.css

@@ -103,7 +103,7 @@ pre .cs, pre .c {
 form .search-query {
     width: 100%;
     border-radius: 50px;
-    padding: 6px 12px;  /* csslint allow: box-model */
+    padding: 6px 12px;
     border-color: #D1D4D5;
 }
 
@@ -135,7 +135,7 @@ form .search-query {
 }
 
 td, th {
-    border: 1px solid #e1e4e5 !important; /* csslint allow: important */
+    border: 1px solid #e1e4e5 !important;
     border-collapse: collapse;
 }
 
@@ -155,6 +155,12 @@ td, th {
     padding-bottom: 40px;
 }
 
+/* For section-index only */
+.wy-menu-vertical .current-section p {
+    background-color: #e3e3e3;
+    color: #404040;
+}
+
 /*
  * The second step of above amendment: Here we make sure the items are aligned
  * correctly within the .rst-current-version container. Using flexbox, we