consistency and cleanup fixes, also added needed solutions to readme

Just fixing the tex's to compile the pdf, some minor consistency to certain files. Additionally, rewrote 09.22.
09.09 was not in solutions.tex, it also contained a solution for 09.17 which I split and added to solutions.tex.
Lastly, I added all the remaining solutions we need still submitted to README at the end, I hope this is ok?
I was kind of surprised by the amount still needed so perhaps other students might find it useful.