Fix list of build types

Change-Id: I244718639e74754d67ee6dbde1eb3cf968e8c874
diff --git a/src/source/building.md b/src/source/building.md
index 5ddcd11..de3bec8 100644
--- a/src/source/building.md
+++ b/src/source/building.md
@@ -44,8 +44,8 @@
 All build targets take the form BUILD-BUILDTYPE, where the BUILD is a codename
 referring to the particular feature combination:
 
-Build name | Device  | Notes
-
+Build name  | Device   | Notes
+------------|----------|---------------------------
 generic     | emulator | lowest-common denominator
 full        | emulator | fully configured with all languages, apps, input methods
 full_crespo | crespo   | `full` build running on Nexus S ("crespo")