- move rotate class to packages/core

- prepare other angle rotate styles
  - refs: https://fastbootstrap.com/docs/rotate/

apps/app/src/styles/style-app.scss

@@ -1,4 +1,5 @@
 @import '@growi/core/scss/flex-expand';
+@import '@growi/core/scss/rotate';
 
 @import 'mixins';
 
@@ -114,8 +115,3 @@
   }
 
 }
-
-.grw-rotate-90 {
-  -webkit-transform: rotate(90deg);
-  transform: rotate(90deg);
-}

packages/core/scss/_rotate.scss

@@ -0,0 +1,16 @@
+// refs: https://fastbootstrap.com/docs/rotate/
+$rotate-degrees: [0, 1, 2, 3, 6, 12, 45, 90, 180];
+
+.rotate-none {
+  transform: none;
+}
+
+@each $degree in $rotate-degrees {
+  .rotate-#{$degree} {
+    transform: rotate(#{$degree}deg);
+  }
+  // negative rotation
+  .-rotate-#{$degree} {
+    transform: rotate(-#{$degree}deg);
+  }
+}