chore(plugin-pnp): add 'pnpm' option in nodeLinker config description (#5850)

**What's the problem this PR addresses?**

Fixes: #5847

**How did you fix it?**

Add 'pnpm' option in nodeLinker config description

**Checklist**
- [x] I have read the [Contributing
Guide](https://yarnpkg.com/advanced/contributing).
- [x] I have set the packages that need to be released for my changes to
be effective.
- [x] I will check that all automated PR checks pass before the PR gets
reviewed.

---------

Co-authored-by: Kristoffer K. <[email protected]>

Author: trivikr

.yarn/versions/64c67350.yml

@@ -0,0 +1,8 @@
+releases:
+  "@yarnpkg/plugin-pnp": patch
+
+declined:
+  - "@yarnpkg/plugin-nm"
+  - "@yarnpkg/plugin-pnpm"
+  - "@yarnpkg/cli"
+  - "@yarnpkg/core"

packages/plugin-pnp/sources/index.ts

@@ -84,7 +84,7 @@ const plugin: Plugin<CoreHooks & StageHooks> = {
   },
   configuration: {
     nodeLinker: {
-      description: `The linker used for installing Node packages, one of: "pnp", "node-modules"`,
+      description: `The linker used for installing Node packages, one of: "pnp", "pnpm", or "node-modules"`,
       type: SettingsType.STRING,
       default: `pnp`,
     },