Add README for activecode

Author: bnmnetp

runestone/activecode/README.md

@@ -0,0 +1,32 @@
+### activecode
+
+```html
+<pre data-component="activecode" id="example1" data-lang="python">
+def main()
+    print("hello world")
+    
+main()
+</pre>
+```
+
+The body of the ``pre`` tag contains code to be loaded into the editor initially.  The following attributes are options and control what pieces and parts of the component will be visible.
+
+* ``data-component`` attribute identifies this as an activecode component
+* ``class``  The usual CSS class options
+* ``id`` must be unique in the document
+* ``data-lang`` for activecode can be python javascript or html
+* ``data-autorun`` run this activecode as soon as the page is loaded
+* ``data-hidecode`` make the editor hidden initially
+* ``data-include`` list of ids of other activecodes.  The code form each will be prepended to the code to run
+* ``data-timelimit`` either False to turn off runtime limit checking or an integer representing the number of milliseconds until timeout.
+* ``data-coach``  add a button to display code coach information
+* ``data-codelens`` add a button "Run this in Codelens"
+
+
+For Python to work in the browser you must also obtain and include via a script tag ``skulpt.min.js`` and 
+``skulpt-stdlib.js`` along with ``codemirror.js`` and of course ``activecode.js``
+
+Soon, many of these requirements will be incorporated into one handy ``runestone.js`` file.
+
+
+