docs(pack): Add section for possible LSP tweaks to Rust (#329)

Co-authored-by: Uzair Aftab <[email protected]>

lua/astrocommunity/pack/rust/README.md

@@ -9,3 +9,33 @@ This plugin pack does the following:
 - Adds [rust-tools.nvim](https://github.com/simrat39/rust-tools.nvim) for language specific tooling
 - Adds [crates.nvim](https://github.com/Saecki/crates.nvim) for crate management
 - Adds [TOML language support](../toml)
+
+## Additional LSP Configuration Tweaks
+
+Configuring the LSP is out of scope for community packs, but here are some interesting things you
+may want to do:
+
+### Make Rust-Analyzer use its own profile
+
+Add this into your LSP configuration to make the rust-analyzer use its own profile. The effect is
+that you will use more disk space as rust-analyzer gets its own special folder in `targets`. The
+upside is that you can run `cargo build` without that being blocked while rust-analyzer runs.
+
+The first three levels of this are AstronVim-specific configurations, the rest is rust-analyzer specific:
+
+```
+  lsp = {
+    config = {
+      rust_analyzer = {
+        settings = {
+          ["rust-analyzer"] = {
+            cargo = {
+              extraEnv = { CARGO_PROFILE_RUST_ANALYZER_INHERITS = 'dev', },
+              extraArgs = { "--profile", "rust-analyzer", },
+            },
+          },
+        },
+      },
+    },
+  },
+```