Add installation instructions

1 files changed, 25 insertions, 1 deletions

diff --git a/README.md b/README.md
index 22a06b6..8c03a70 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,26 @@
 # node-dhall-json
-NPM package for `dhall-json`, based on https://github.com/justinwoo/npm-psc-package-bin-simple.
+NPM package for `dhall-json`, based on https://github.com/justinwoo/npm-psc-package-bin-simple. Linux and Windows only.
+
+## Installation
+
+:warning: This package should be installed as an optional dependency until static macOS builds are available from [`dhall-haskell` releases](https://github.com/dhall-lang/dhall-haskell/releases).
+
+There’s two installation modes:
+
+### Locked
+
+```
+npm install --save-optional fretlink/node-dhall-json#v<dhall-json version>-<dhall version>-<package version>
+```
+
+This will install a specific version of `dhall-json`. Replace `<dhall-json version>`, `<dhall version>` and `<package version>` with appropriate versions of `dhall-json`, `dhall` and this package.
+
+See [the releases](https://github.com/fretlink/node-dhall-json/releases).
+
+### Dynamic
+
+```
+npm install --save-optional fretlink/node-dhall-json
+```
+
+This will install a version of `dhall-json` matching the `DHALL_JSON_VERSION` and `DHALL_VERSION` environment variables or the `dhall-json:dhall-json-version` and `dhall-json:dhall-version` [npm configuration settings](https://docs.npmjs.com/misc/config#per-package-config-settings).