feat: add pnpm support (#452)

* feat: add pnpm support

* fix lint empty line

* type in example description

src/commands/install.yml

@@ -45,7 +45,7 @@ parameters:
     default: ""
   package-manager:
     type: enum
-    enum: ["npm", "yarn", "yarn-berry"]
+    enum: ["npm", "yarn", "yarn-berry", "pnpm"]
     default: "npm"
     description: Select the default node package manager to use. NPM v5+ Required.
 

src/examples/pnpm.yml

@@ -0,0 +1,14 @@
+description: >
+  Runs Cypress tests using pnpm.
+  Installs dependencies and caches NPM modules and the Cypress binary.
+usage:
+  version: 2.1
+  orbs:
+    cypress: cypress-io/cypress@3
+  workflows:
+    use-my-orb:
+      jobs:
+        - cypress/run:
+            package-manager: "pnpm"
+            start-command: "pnpm start"
+            install-command: "pnpm install --frozen-lockfile"

src/jobs/run.yml

@@ -49,7 +49,7 @@ parameters:
     default: ""
   package-manager:
     type: enum
-    enum: ["npm", "yarn", "yarn-berry"]
+    enum: ["npm", "yarn", "yarn-berry", "pnpm"]
     default: "npm"
     description: Select the default node package manager to use. NPM v5+ Required.
   start-command: