Guidelines.

Added guidelines with instructions.

guidelines/Instructions.md

@@ -0,0 +1,19 @@
+# Guidelines
+
+* **Green** is the safe zone, where the main body of the icon should be.
+    
+* **Yellow** is like a road shoulder, it's there if more space is needed. It should be used for protruding elements, like corners or ornaments.
+
+* **Red** is off limits. It should not be touched by the icons. Red is also how a circular icon would look.
+
+## guideline.svg
+
+This is the standard guideline. It helps with sizing for both square and circle icons, so they would look good no matter what border radius is chosen.
+
+## guideline for small squares.svg
+
+This guideline solves visibility  problems with sizing for both squares and circles, where it might end up a bit small for good visibility when displayed at very, very small sizes in square form.
+
+——
+
+Needless to say, these are just guides. If they don't accommodate a certain shape, then they shouldn't be followed strictly.