Cargo fix and readme updates

[dantheman3333]

Hi, made some minor cleanups:

• tinygrad from pip worked fine for me (on linux) so I added it to the requirements file - is this an issue on other platforms?
• Updated the readme on the commands used to set up the virtual env
  • I placed it in the python dir, feel free to move or remove
  • Removed the download of the tokenizer in the convert step as it doesn't seem to be necessary and is included in step 2 Download
• Applied cargo fix. There are a lot of unused functions left untouched