fix(node.js) Update documentation related to devDependencies pruning

src/_posts/languages/nodejs/2000-01-01-deployment-errors.md

@@ -10,21 +10,21 @@ You may experience an error in your Node.js application that many customers
 faced when first deploying such application on Scalingo. Here is a list of the
 most common error messages.
 
-## devDependencies Also Contain the Build Dependencies {#dep}
+## devDependencies Also Contain Some Dependencies Required at Startup or Runtime {#dep}
 
-The `devDependencies` section of the package.json file contains both development
-dependencies and build dependencies. By default Scalingo deployments install the
-dependencies from the `dependencies` section of the package.json file. It may
+The `devDependencies` section of the package.json file contains dependencies required
+during startup of the app, or during runtime. By default, Scalingo deployments prune the
+dependencies from the `devDependencies` section of the package.json file. It may
 lead to error messages such as `ng: not found` or `nest: not found`. In such
 situation, you have a couple of solutions:
 
-- Install all `devDependencies` ([doc]({% post_url
-    languages/nodejs/2000-01-01-start %}#install-devdependencies)).
+- Use yarn v2+ and skip pruning dependencies ([doc]({% post_url
+    languages/nodejs/2000-01-01-start %}#devdependencies-installation)).
 
   ```bash
-  $ scalingo --app my-app env-set NPM_CONFIG_PRODUCTION=false
+  $ scalingo --app my-app env-set YARN2_SKIP_PRUNING=true
   ```
-- Move the `devDependencies` needed for the build into the `dependencies`
+- Move the `devDependencies` needed for runtime into the `dependencies`
     section of the package.json file.
 
 ## Boot Timeout {#timeout}

src/_posts/languages/nodejs/2000-01-01-start.md

@@ -96,22 +96,11 @@ environment.
 
 By default, dependencies present in the `devDependencies` field are installed. At the end of the deployment, `devDependencies` are pruned. Hence only production dependencies are left in the image used for the runtime.
 
-The pruning step can be skipped by setting the environment variable `YARN_PRODUCTION` to any value.
+`devDependencies` can be totally ignored and not installed at all by setting `NPM_CONFIG_PRODUCTION=true` npm or `YARN_PRODUCTION=true` with yarn v1.
 
 #### Skip Pruning
 
-If you need access to packages declared under devDependencies at runtime or in a different buildpack then, depending on the package manager used, you can set one of the following environment variables to skip the pruning step:
-
-| Package manager | Version | Environment variable    | Value   |
-|-----------------|---------|-------------------------|---------|
-| npm             | Any     | `NPM_CONFIG_PRODUCTION` | `true`  |
-| yarn            | v1      | `YARN_PRODUCTION`       | `true`  |
-| yarn            | v2+     | `YARN2_SKIP_PRUNING`    | `true`  |
-
-
-Then you can use this CLI command pattern: `scalingo --app my-app env-set variable=value`
-
-Example for npm : `scalingo --app my-app env-set NPM_CONFIG_PRODUCTION=true`
+If you need access to packages declared under `devDependencies` at runtime - or in a different buildpack - then you'll need to use yarn v2+ and set `YARN2_SKIP_PRUNING=true`.
 
 ### Ensure you're Tracking all your Dependencies