Manage node version via .nvmrc

Inspired by @K-dizzled

Author: GlebSolovev

.github/workflows/coqpilot.yml

@@ -43,10 +43,9 @@ jobs:
       run: eval $(opam env)
 
     - name: Install Node.js
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v4 
       with:
-        node-version: ">=20.5.0"
-
+        node-version-file: ".nvmrc"
     - run: npm ci
 
     - name: Check coq-lsp version
@@ -106,9 +105,9 @@ jobs:
     if: github.ref == 'refs/heads/main'
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-node@v3
+      - uses: actions/setup-node@v4
         with:
-          node-version: ">=20.5.0"
+          node-version-file: ".nvmrc"
       - name: Install Dependencies
         run: npm ci
       - name: Download Build Artifact

.nvmrc

@@ -0,0 +1 @@
+20.13.1

README.md

@@ -74,7 +74,19 @@ With coq-lsp, extension should have everything it needs to run.
 
 ### Building locally
 
-To build the extension locally, you will need to have `npm` installed. Then you can clone the repository and run the following commands:
+First, clone the Coqpilot repository and navigate into its directory.
+```bash
+git clone https://github.com/JetBrains-Research/coqpilot.git
+cd coqpilot
+```
+
+To build the extension locally, you'll need Node.js installed. The recommended way to manage Node.js versions is by using `nvm`. From the Coqpilot root directory, execute:
+```bash
+nvm use
+```
+If you prefer not to use `nvm`, ensure you install the Node.js version specified in the [`.nvmrc`](.nvmrc) file by any other method you prefer.
+
+Once Node.js is installed, the remaining setup will be handled by the `npm` package manager. Run the following commands:
 ```bash
 npm install
 npm run compile