Drop nightly requirement

docs/src/developing.md

@@ -28,7 +28,7 @@ Feature branches are not required, there are also changes happening directly on
 
 You will need the following tools:
 
-* Rust (obviously) (easiest via `rustup`), with the nightly toolchain
+* Rust (obviously) (easiest via `rustup`)
 * Python3
 * [`just`](https://github.com/casey/just), a command runner like `make`. See
   [here](https://github.com/casey/just#installation) for installation
@@ -52,18 +52,3 @@ mvdan.cc/sh/v3/cmd/shfmt@latest`, depending on your go build environment.
 
 For details about rustup and the toolchains, see [the installation
 section](./installation.md).
-
-## FAQ
-
-### Why nightly?
-
-For now, GRM requires the nightly toolchain for two reasons:
-
-* [`io_error_more`](https://github.com/rust-lang/rust/issues/86442) to get
-  better error messages on IO errors
-* [`const_option_ext`](https://github.com/rust-lang/rust/issues/91930) to have
-  static variables read from the environment that fall back to hard coded
-  defaults
-
-Honestly, both of those are not really necessary or can be handled without
-nightly. It's just that I'm using nightly anyway.