Update README with detailed usage instructions; switch workflows to MiniServ-nix-runner

.gitea/workflows/test.yml

@@ -42,7 +42,19 @@ jobs:
           index = "sparse+https://git.moturpin.com/api/packages/Matsubaa/cargo/"
           EOF
 
+      - name: Write Cargo credentials
+        env:
+          CARGO_TOKEN: ${{ secrets.CARGO_TOKEN }}
+        run: |
+          mkdir -p ~/.cargo
+          umask 077
+          cat > ~/.cargo/credentials.toml <<'EOF'
+          [registries.gitea]
+          token = "${CARGO_TOKEN}"
+          EOF
+
       - name: Publish to Gitea Cargo registry
         env:
           CARGO_REGISTRIES_GITEA_TOKEN: ${{ secrets.CARGO_TOKEN }}
-        run: nix develop --extra-experimental-features "nix-command flakes" -c cargo publish --registry gitea --verbose
+          CARGO_TOKEN: ${{ secrets.CARGO_TOKEN }}
+        run: nix develop --extra-experimental-features "nix-command flakes" -c cargo publish --registry gitea --token "${CARGO_TOKEN}" --verbose