Docs/variables data (#1314)

* Replace variables.json with colors.json and update related files accordingly

* Add variables data files

* Update variables include template and all related files to use new variables data

* Fix mobile breakpoint id typo in responsivness docs page

* Fix Liquid syntax error in made-with-bulma docs page

* Update bulma sass files count in modular docs page

* Use breakpoints data in responsiveness helpers docs page

* Use breakpoints and variables data in typography helpers docs page

* Add missing page titles in docs pages front matter

docs/_data/variables/elements/image.json

@@ -0,0 +1,15 @@
+{
+  "dir_name": "elements",
+  "file_name": "image",
+  "file_relative_path": "elements/image.sass",
+  "file_line_from": 1,
+  "file_line_to": 1,
+  "file_url": "https://github.com/jgthms/bulma/blob/master/sass/elements/image.sass#L1,L1",
+  "vars": {
+    "dimensions": {
+      "id": "dimensions",
+      "name": "$dimensions",
+      "value": "16 24 32 48 64 96 128"
+    }
+  }
+}