Add instructions for radare2 support to the readme.

Author: aweinstock314

README.md

@@ -21,7 +21,8 @@ The basic process is simple and looks like this:
 
 1. Clone the repo to your local machine
 2. Place the repo into your Binary Ninja plugins directory, or create a symlink pointing to it.
-3. (Optional) Install PyQt5 - The latest version of ripr does not require this.
+3. (Optional) Add `(ripr addr, #!pipe python /absolute/path/to/ripr/r2pipe_run.py $0)` to your `.radare2rc`.
+4. (Optional) Install PyQt5 - The latest version of ripr does not require this.
 
 #### Windows
 Installation on Windows typically requires installing PyQt5.
@@ -35,6 +36,7 @@ Installation on Windows typically requires installing PyQt5.
 ---
 
 #### Packaging a Function
+##### Binary Ninja
 From within Binary Ninja, right click anywhere inside of a function and select `[ripr] Package Function`.
 
 <img src="https://puu.sh/thLAo/491ac39e58.PNG" width="600">
@@ -43,6 +45,10 @@ After packaging, a table will appear listing all of the "packages" you have crea
 
 <img src="https://puu.sh/tnz8C/d0f5141f43.PNG" width="600">
 
+##### Radare2
+If you've followed step 3 in the installation instructions, run `.(ripr 0x1234)` (with 0x1234 replaced by the address of the function).
+Otherwise, you can manually invoke ripr with `#!pipe python /absolute/path/to/ripr/r2pipe_run.py 0x1234`.
+
 #### Packaging Specific Basic Blocks
 You can also choose to only package specific basic blocks rather than the entire function.