docs: update installation instructions to use mise

Amolith created 

Replace bin with mise as the recommended tool for automated CLI
management. The old bin install command has been replaced with mise's
use -g go: syntax which provides equivalent functionality.

Change summary

README.md | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

Detailed changes

README.md 🔗 

@@ -41,11 +41,11 @@ lune habit track meditation            # Track a habit
 
 ## Installation
 
-- Using [bin](https://github.com/marcosnils/bin) (recommended to
-  centralise and automate updating of binaries/CLI tools like this, but
-  still requires the Go toolchain):
+- Using [mise](https://mise.jdx.dev/) (recommended to centralise and automate
+  updating of binaries/CLI tools like this, but still requires the Go
+  toolchain):
   ```bash
-  bin install goinstall://git.secluded.site/lune@latest
+  mise use -g go:git.secluded.site/lune@latest
   ```
 - Using the [Go toolchain](https://go.dev/dl) without bin (requires
   tracking updates manually):