Improve readme generation

Allows specifying the location of the readme file in the .csproj metadata, so that the file can appear next to the templates in a sub-directory.

MSBuild support

Updated to include MSBuild support. See the readme for more details on usage.

Also updates to handle file templates better.

Fix invalid cast exception

• Fixed InvalidCastException when loading .dotSettings file (#1) - thanks @wangzq!

v1.2 - Escape filename + normalise text

• Escapes the shortcut to make a valid filename
• Ensures markdown file is truncated when overwriting
• Normalises the line endings when writing the text

v1.1 - Handle optional values

Update to handle optional values, mainly description and categories

v1.0

Initial release. Decompile templates from existing .dotSettings files into human readable markdown files, then recompile back to a .dotSettings file for ease of distribution.