Make shell commands in README easier to copy (#114)

* Update README.md

* Tweak copy

---------

Co-authored-by: Niklas Higi <niklas@higi.dev>

README.md

@@ -21,7 +21,7 @@ You can also use `apk-mitm` to [patch apps using Android App Bundle](#patching-a
 If you have an up-to-date version of [Node.js][node] (14+) and [Java][java] (8+), you can install `apk-mitm` by running:
 
 ```shell
-$ npm install -g apk-mitm
+npm install -g apk-mitm
 ```
 
 ## Usage
@@ -29,10 +29,10 @@ $ npm install -g apk-mitm
 Once installed, you can run this command to patch an app:
 
 ```shell
-$ apk-mitm <path-to-apk>
+apk-mitm <path-to-apk>
 ```
 
-So, if your APK file is called `example.apk`, you'd run:
+Patching an APK file called `example.apk` might look like this:
 
 ```shell
 $ apk-mitm example.apk