docs(rust): fix incorrect snippet for setting up different profiles

lua/astrocommunity/pack/rust/README.md

@@ -1,4 +1,5 @@
 # Rust Language Pack
+
 This plugin pack does the following:
 
 - Adds `rust` Treesitter parsers
@@ -20,21 +21,24 @@ Add this into your LSP configuration to make the rust-analyzer use its own profi
 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:
+The following can be added to the configuration of AstroLSP to customize the profiles used by rust-analyzer.
 
-```
-  lsp = {
+```lua
+return {
+  "AstroNvim/astrolsp",
+  opts = {
     config = {
       rust_analyzer = {
         settings = {
           ["rust-analyzer"] = {
-           cargo = {
-              extraEnv = { CARGO_PROFILE_RUST_ANALYZER_INHERITS = 'dev', },
-              extraArgs = { "--profile", "rust-analyzer", },
+            cargo = {
+              extraEnv = { CARGO_PROFILE_RUST_ANALYZER_INHERITS = "dev" },
+              extraArgs = { "--profile", "rust-analyzer" },
             },
           },
         },
       },
     },
   },
+}
 ```