Updated Building and Testing (markdown)

Building-and-Testing.md

@@ -39,6 +39,17 @@ It will perform four simple tasks:
  3. copy `guided.py` into the root git folder due to how the import works in Python
  4. Finally it will run the latest version of `guided.py`
 
+### Step 5: Build
+
+[Archiso](https://wiki.archlinux.org/index.php/Archiso#Build_the_ISO) has great information and the latest info.
+But in general, all you need to do (standing in the arciso folder), is to run:
+
+```bash
+# mkarchiso -v -w work/ -o out/ ./
+```
+
+And that should produce your ISO.
+
 ----
 
 For a simple script that builds, boots and does all this automatically.