SkQP: update README.md

No-Try: true
Change-Id: I7b12f683901ece91e3a7e2d9fa432aa05fbcf12a
Reviewed-on: https://skia-review.googlesource.com/108568
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
diff --git a/tools/skqp/README.md b/tools/skqp/README.md
index da8f9ef..3583d2a 100644
--- a/tools/skqp/README.md
+++ b/tools/skqp/README.md
@@ -5,8 +5,10 @@
 Test Suite) that tests an Android device's GPU and OpenGLES & Vulkan drivers
 using Skia's existing unit & rendering tests.
 
-How to run the SkQP tests
--------------------------
+See https://skia.org/dev/testing/skqp for pre-build APKs.
+
+How to build and run the SkQP tests
+-----------------------------------
 
 1.  Get the dependencies:
 
@@ -20,7 +22,7 @@
     -   Install the [Android NDK](https://developer.android.com/ndk/downloads/).
 
             ( cd ~; unzip ~/Downloads/android-ndk-*.zip )
-            ANDROID_NDK=$(ls ~/android-ndk-*)   # Or wherever you installed the Android NDK.
+            ANDROID_NDK=$(ls -d ~/android-ndk-*)   # Or wherever you installed the Android NDK.
 
     -   Install the [Android SDK](https://developer.android.com/studio/#command-tools).
         Set the `ANDROID_HOME` environment variable.