Move yoga docs into docs folder on master branch

Summary: Move yoga docs into master branch so that pull requests are able to include doc updates as part of other changes.

Reviewed By: JoelMarcey

Differential Revision: D4365700

fbshipit-source-id: 2f46a88974104c454c00bcdf1257abb5c4075a68

docs/_sass/_buttons.scss

@@ -0,0 +1,47 @@
+.button {
+  border: 1px solid $primary-bg;
+  border-radius: 3px;
+  color: $primary-bg;
+  display: inline-block;
+  font-size: 14px;
+  font-weight: 900;
+  line-height: 1.2em;
+  padding: 10px;
+  text-transform: uppercase;
+  transition: background 0.3s, color 0.3s;
+
+  &:hover {
+    background: $primary-bg;
+    color: $primary-overlay;
+  }
+}
+
+.homeContainer {
+  .button {
+    border-color: $homeContainer-button-color;
+    border-width: 1px;
+    color: $homeContainer-button-color;
+
+    &:hover {
+      background: $homeContainer-button-color;
+      color: $primary-bg;
+    }
+  }
+}
+
+.blockButton {
+  display: block;
+}
+
+.edit-page-link {
+    float: right;
+    font-size: 14px;
+    font-weight: normal;
+    line-height: 20px;
+    opacity: 0.6;
+    transition: opacity 0.5s;
+}
+
+.edit-page-link:hover {
+  opacity: 1;
+}