chore: regenerate README (#786)

This PR was generated using Autosynth. 🌈


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

```
2020-10-06 22:16:04,080 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-bigquery/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working directory clean
2020-10-06 22:16:05,141 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/c26ebe34-013c-45a3-b042-08c9367790b2/targets

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

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

@@ -0,0 +1,18 @@
+{
+  "sources": [
+    {
+      "git": {
+        "name": ".",
+        "remote": "https://github.com/googleapis/java-bigquery.git",
+        "sha": "038e55d860a1a9c4ce1b77dbd06fae8468ab4897"
+      }
+    },
+    {
+      "git": {
+        "name": "synthtool",
+        "remote": "https://github.com/googleapis/synthtool.git",
+        "sha": "487eba79f8260e34205d8ceb1ebcc65685085e19"
+      }
+    }
+  ]
+}

README.md

@@ -19,7 +19,7 @@ See https://github.com/GoogleCloudPlatform/cloud-opensource-java/wiki/The-Google
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>libraries-bom</artifactId>
-      <version>10.0.0</version>
+      <version>11.1.0</version>
       <type>pom</type>
       <scope>import</scope>
     </dependency>
@@ -40,7 +40,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-bigquery</artifactId>
-  <version>1.117.1</version>
+  <version>1.120.0</version>
 </dependency>
 
 ```
@@ -174,6 +174,7 @@ has instructions for running the samples.
 | Query Destination Table Cmek | [source code](https://github.com/googleapis/java-bigquery/blob/master/samples/snippets/src/main/java/com/example/bigquery/QueryDestinationTableCmek.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/QueryDestinationTableCmek.java) |
 | Query Disable Cache | [source code](https://github.com/googleapis/java-bigquery/blob/master/samples/snippets/src/main/java/com/example/bigquery/QueryDisableCache.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/QueryDisableCache.java) |
 | Query Dry Run | [source code](https://github.com/googleapis/java-bigquery/blob/master/samples/snippets/src/main/java/com/example/bigquery/QueryDryRun.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/QueryDryRun.java) |
+| Query External Bigtable Temp | [source code](https://github.com/googleapis/java-bigquery/blob/master/samples/snippets/src/main/java/com/example/bigquery/QueryExternalBigtableTemp.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/QueryExternalBigtableTemp.java) |
 | Query External Gcs Perm | [source code](https://github.com/googleapis/java-bigquery/blob/master/samples/snippets/src/main/java/com/example/bigquery/QueryExternalGcsPerm.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/QueryExternalGcsPerm.java) |
 | Query External Gcs Temp | [source code](https://github.com/googleapis/java-bigquery/blob/master/samples/snippets/src/main/java/com/example/bigquery/QueryExternalGcsTemp.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/QueryExternalGcsTemp.java) |
 | Query External Sheets Perm | [source code](https://github.com/googleapis/java-bigquery/blob/master/samples/snippets/src/main/java/com/example/bigquery/QueryExternalSheetsPerm.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/QueryExternalSheetsPerm.java) |