feat: mips, mars support

[WillLillis]

This adds support for the mips architecture and mars assembler

• Instructions were sourced from here (by hand): https://www.cs.cornell.edu/courses/cs3410/2008fa/MIPS_Vol2.pdf
• Mars pseudo-ops were sourced from here (parsed): https://github.com/dpetersanderson/MARS/blob/main/PseudoOps.txt
• Mars directives (surely there's more than 3?) were sourced from here (by hand): https://dpetersanderson.github.io/Help/MacrosHelp.html

The server can be configured to work with mips and mars with the following .asm-lsp.toml file:

[default_config]
version = "0.10.0"
assembler = "mars"
instruction_set = "mips"

[default_config.opts]
compiler = "mars"
compile_flags_txt = ["a"]
diagnostics = true
default_diagnostics = false

• Closes feat: Add MIPS architecture #245

Merge Checklist:

• Add registers
• Add tests
• Add references to documentation in README
  • https://en.wikibooks.org/wiki/MIPS_Assembly/Register_File