* tutorial: preprocess.py: Fix leading whitespace

This fixes the indentation of metadata in `preprocess.py` in the TVMC tutorial, removing the leading whitespaces in the HTML rendering[^1].

[^1] https://tvm.apache.org/docs/tutorial/tvmc_command_line_driver.html#preprocess-py



* tutorial: Add missing code block escapes

* tutorial: Grammar fixup

* README.md: Fix link to introduction

Co-authored-by: Martin Kröning <martin.kroening@neclab.eu>