Exclude image captions from auto-linking API symbols.

Currently we are processing back-ticks inside of `![image](/url.png "caption \`symbol\`")`, but this breaks the markdown, and probably the author's expectation too.

PiperOrigin-RevId: 488842017

Author: markmcd

tools/tensorflow_docs/api_generator/reference_resolver.py

@@ -297,7 +297,9 @@ def one_ref(match):
                           '</pre>'),
         IgnoreLineInBlock('```', '```'),
         IgnoreLineInBlock(
-            '<pre class="devsite-click-to-copy prettyprint lang-py">', '</pre>')
+            '<pre class="devsite-click-to-copy prettyprint lang-py">',
+            '</pre>'),
+        IgnoreLineInBlock('![', ')'),  # Don't replace within image's caption
     ]
 
     for line in string.splitlines():