Docs: Give documentation examples better names

These names come from the bookmaker generated md files.

Also, delete ducplicated and empty examples.

A later CL will re-name the cpp files.

Change-Id: Ie365b9cc1cc705d010c674b9988b32c8307a0455
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/201609
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Hal Canary <halcanary@google.com>
diff --git a/docs/examples/RRect_013.cpp b/docs/examples/RRect_013.cpp
index f0fbcbe..8673a10 100644
--- a/docs/examples/RRect_013.cpp
+++ b/docs/examples/RRect_013.cpp
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
 #include "fiddle/examples.h"
 // HASH=5a3eb1755164a7becec33cec6e6eca31
-REG_FIDDLE(RRect_013, 256, 256, true, 0) {
+REG_FIDDLE(RRect_height, 256, 256, true, 0) {
 void draw(SkCanvas* canvas) {
     SkRRect unsorted = SkRRect::MakeRect({ 15, 25, 10, 20 });
     SkDebugf("unsorted height: %g\n", unsorted.height());