fix(store): mention pnpm store path in help output

.changeset/quiet-mugs-visit.md

@@ -0,0 +1,5 @@
+---
+"@pnpm/plugin-commands-store": patch
+---
+
+Add `pnpm store path` to help of `pnpm store`

packages/plugin-commands-store/src/store.ts

@@ -47,6 +47,10 @@ Pruning the store is not harmful, but might slow down future installations. \
 Visit the documentation for more information on unreferenced packages and why they occur',
             name: 'prune',
           },
+          {
+            description: 'Returns the path to the active store directory.',
+            name: 'path',
+          },
         ],
       },
     ],