Add Zephyr to supported toools

Author: th-awake

README.md

@@ -4,14 +4,19 @@ A GitHub Action which sets up a PureScript toolchain for CI. Contains the follow
 
 - The [PureScript compiler](https://github.com/purescript/purescript)
 - The [Spago package manager and build tool](https://github.com/purescript/spago)
+- The [Zephyr dead code elimination tool](https://github.com/coot/zephyr)
+
+This action is designed to support tools with static binaries. Your PureScript project may also depend on tooling and libraries provided by the NPM ecosystem, in which case you will also want to use the [setup-node](https://github.com/actions/setup-node) action.
+
+> Note: While this action does work, it is currently under development and the API may change. Feel free to experiment using it, but it won't be stable until a v1 release when the PureScript Contributor organization switches to use it.
 
 ## Usage
 
 See the [action.yml](action.yml) file for all possible inputs and outputs.
 
 ### Basic
 
-Get the latest versions of PureScript and Spago in the environment:
+Get the latest versions of PureScript, Spago, and Zephyr in the environment:
 
 ```yaml
 steps:
@@ -22,7 +27,7 @@ steps:
 
 ### Use Specific Versions
 
-Use specific versions of PureScript and/or Spago by supplying a valid semantic version (only exact versions currently supported):
+Use specific versions of any tool by supplying a valid semantic version (only exact versions currently supported):
 
 ```yaml
 steps:
@@ -31,5 +36,19 @@ steps:
     with:
       purescript-version: "0.13.8"
       spago-version: "0.15.3"
+      zephyr-version: "0.3.2"
+  - run: spago build
+```
+
+### Cache Library Dependencies (Coming Soon)
+
+Automatically build and cache library dependencies between workflow runs by supplying a path to a Spago config file:
+
+```yaml
+steps:
+  - uses: actions/checkout@v2
+  - uses: thomashoneyman/setup-purescript@master
+    with:
+      cache: "spago.dhall"
   - run: spago build
 ```

action.yml

@@ -8,6 +8,9 @@ inputs:
   spago-version:
     description: "The Spago version to install. Examples: latest, 0.15.3"
     default: "latest"
+  zephyr-version:
+    description: "The Zephyr version to install. Examples: latest, 0.3.2"
+    default: "latest"
 runs:
   using: "node12"
   main: "dist/index.js"