chore: regenerate README (#250)

This PR was generated using Autosynth. 🌈


<details><summary>Log from Synthtool</summary>

```
2020-10-30 21:00:57,460 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-document-ai/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working directory clean
2020-10-30 21:00:58,392 synthtool [DEBUG] > Wrote metadata to .github/readme/synth.metadata/synth.metadata.

```
</details>

Full log will be available here:
https://source.cloud.google.com/results/invocations/635f3aad-ec71-4a9e-bcfe-eb1f981b112a/targets

- [ ] To automatically regenerate this PR, check this box.

Author: yoshi-automation

.github/readme/synth.metadata/synth.metadata

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-document-ai.git",
-        "sha": "28d0b0dfe2fa55786df75d4d196c91c64b590b8a"
+        "sha": "55cbf94adcc76cbfeef92b351bf2ffa4b61a851e"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "ea52b8a0bd560f72f376efcf45197fb7c8869120"
+        "sha": "6542bd723403513626f61642fc02ddca528409aa"
       }
     }
   ]

README.md

@@ -31,7 +31,7 @@ If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file
   <dependency>
     <groupId>com.google.cloud</groupId>
     <artifactId>google-cloud-document-ai</artifactId>
-    <version>0.3.2</version>
+    <version>0.3.3</version>
   </dependency>
 
 ```
@@ -42,7 +42,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-document-ai</artifactId>
-  <version>0.3.2</version>
+  <version>0.3.3</version>
 </dependency>
 
 ```