Update README.md

Author: cxcorp

README.md

@@ -1,2 +1,15 @@
 # explainshell-cli-opener
-Write a command-line and open its explainshell.com explanation in a browser automatically
+Write a command-line and open its explainshell.com explanation in a browser automatically.
+
+Works on Linux, macOS, and Windows in WSL2.
+
+## Installation
+
+1. Install [`jq`](https://stedolan.github.io/jq/download/). You can `sudo apt-get install jq` or `brew install jq`.
+2. Copy `main.sh` into some directory in your `PATH`, e.g. probably `~/.local/bin` or `/usr/local/bin` or something.
+3. Give yourself the permissions to run the script: `chmod u+x main.sh`
+4. Name the file something nice, like `wtf`
+5. Run it:
+   ```
+   wtf tar -xzvf foo.tar.gz
+   ```