Remove note about the dev branch in the readme (#388)

Since this repository no longer does all the development on a dev branch the instructions in the readme noting this are no longer accurate.

Therefore this PR removes this note, and since this was the only instruction outside of the "Getting started", I've removed the "Instructions" header and upgraded the "Getting started" header.

README.md

@@ -39,12 +39,7 @@ and a single input can result in multiple actions being triggered, which can be
 
 - Gamepads must be manually assigned to each input map: read from the `Gamepads` resource and use `InputMap::set_gamepad`.
 
-## Instructions
-
-**Development occurs on the `dev` branch, which is merged into `main` on each release.**
-This ensures the examples are in-sync with the latest release.
-
-### Getting started
+## Getting started
 
 1. Add `leafwing-input-manager` to your `Cargo.toml`.
 2. Create an enum of the logical actions you want to represent, and derive the `Actionlike` trait for it.