docs: brew install with the one-command form

brew install accepts a fully-qualified tap path and taps implicitly,
so the separate brew tap step is noise for a first-time user.

README.md

@@ -16,20 +16,7 @@ sudo snap connect ecrou:kvm
 
 macOS (Apple Silicon, Homebrew):
 ```
-brew tap vhaudiquet/ecrou https://github.com/vhaudiquet/homebrew-ecrou
+brew install vhaudiquet/ecrou/ecrou
-brew install ecrou
-```
-
-The macOS build loads libkrun from the
-[`libkrun/homebrew-krun`](https://github.com/libkrun/homebrew-krun) tap
-at runtime and boots through Hypervisor.framework; the formula signs
-the binary with the hypervisor entitlement macOS requires, so the
-install needs no extra steps. Building from source instead:
-
-```
-brew install libkrun/homebrew-krun/libkrun e2fsprogs
-cargo build --release -p ecrou-cli
-codesign --force --sign - --entitlements packaging/macos/ecrou.entitlements   target/release/ecrou
 ```
 
 ### Usage