Reorganize the module structure

[max-ishere]

Currently there are 2 modules: parser and render. Each contains submodules for theme.txt and the pff2 font. However it seems like this structure doesnt work all that well and would have to be reorganized.

The best time to do this is after everything is parsable into Rusty structs. Then the rusty structs go into the module that will be exposed to the users, which can then be borrowed by the module that does the rendering (just PNG making really) or if the user of the lib wants to parse some files (e.g. to display it in a nice way in an editor) they can do that too.

The main issue is that these modules at the moment dont do what they say they do. parser does parse the files, but render takes parser structs and turns them into something validated. The only exception is perhaps some implementations for Glyph rendering