Add support for generating clangd compile_commands.json config (#38)

* Implement support for generating clangd `compile_commands.json` config

* Add example .clangd file

* Tidy .gitignore and add entries for clangd and other things

* couple things i forgot to remove

* Change indent level to 2

* Centralize file type checking logic

* Refactor flag replacments to fix `-lang=` flags not being handled

* Move language flag fallback addition to `generate_build_ninja`

* Remove file type flags from .clangd example

* Remove clangd compiler defines option
Projects which need it can define things themselves in .clangd

* Move global clangd flags to tools/project.py & update vscode config

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Co-authored-by: Luke Street <luke@street.dev>

tools/download_tool.py

@@ -55,6 +55,7 @@ def dtk_url(tag: str) -> str:
     repo = "https://github.com/encounter/decomp-toolkit"
     return f"{repo}/releases/download/{tag}/dtk-{system}-{arch}{suffix}"
 
+
 def objdiff_cli_url(tag: str) -> str:
     uname = platform.uname()
     suffix = ""