adding initial files for sphinx documentation

Just added the files and directories that would be used for making Sphinx documentation.
More needs to be added, especially in the future, but this is an important start.
I didn't include the output of a build as it generates a log of "junk" that we might not want, since we can just generate it when we need it.
During the setup of Sphinx, I was given the option of .rst or .txt files, I chose .txt files as I figured that was easier to make and edit (that is, no unreasonable default program would try to be used if you just clicked and selected "Edit/Open").

.rst files should still work, I just picked that as I know that .txt files are just files of text, and didn't know what .rst might be otherwise