docs: clarify language around luarocks when building from source

.github/workflows/nix-build.yaml

@@ -21,4 +21,4 @@ jobs:
       - uses: DeterminateSystems/magic-nix-cache-action@main
 
       - name: Build with Nix
-        run: nix build .#blink-cmp
+        run: nix build .#blink-cmp -Lv

README.md

@@ -39,7 +39,7 @@
   -- recommended: use a release tag for stable releases and prebuilt binaries, when not using luarocks
   version = 'v0.*',
 
-  -- optionally: build from source, requires nightly: https://rust-lang.github.io/rustup/concepts/channels.html#working-with-nightly-rust
+  -- optionally: build from source, when not using luarocks, requires nightly: https://rust-lang.github.io/rustup/concepts/channels.html#working-with-nightly-rust
   -- build = 'cargo build --release',
   -- If you use nix, you can build from source using latest nightly rust with:
   -- build = 'nix run .#build-plugin',