Add 0.6.2 version of MDwiki

… along with a README that explains briefly how to update to a later version in the future.

README.md

@@ -0,0 +1,18 @@
+For Developers
+==============
+
+You don't need to read below here or do anything at all if you're only interested creating your own wiki. This section is for developers or maintainers of this repository.
+
+Update MDwiki
+-------------
+
+> Current version: [0.6.2](http://git.io/HBH5Wg).
+
+1. Go to https://github.com/Dynalon/mdwiki/releases/latest
+1. Click on the green button on that page to download the latest release
+1. Extract the contents of the archive file
+1. Copy `mdwiki-slim.html` file from the extracted files onto `index.html` file in this repository by renaming, thus overriding `index.html`
+1. Update the version information above
+1. Commit and push your changes
+
+You can now delete any files downloaded previously, if you want to.