doc: Write lots of docs

Documentation/debugger.rst

Documentation/epicardium/api.rst

Documentation/epicardium/intro.rst

Documentation/epicardium/overview.rst

Documentation/how-to-build.rst

Documentation/how-to-flash.rst

Documentation/index.rst

Documentation/overview.rst

Documentation/pycardium/intro.rst

Documentation/pycardium/overview.rst

Documentation/static/overview.svg

Documentation/static/synchroneous-api-call.dia

Documentation/static/synchroneous-api-call.svg