chore: regenerate README (#1502)

This PR was generated using Autosynth. 🌈


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

```
2021-08-12 22:28:59,302 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-bigquery/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-08-12 22:29:00,947 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/b6043864-4086-4be6-aae5-78530bd566d0/targets

- [ ] To automatically regenerate this PR, check this box. (May take up to 24 hours.)

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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-bigquery.git",
-        "sha": "70abb812b3ebfa47d70dccd936a65c10f35b4817"
+        "sha": "855faeb5c220ae951735fc340242f187be35dc6f"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "5605f38f153e7627ba4441a2c5181060b664d224"
+        "sha": "ff01716e16d2c6e87eaf87197b753ac9fcbbed5d"
       }
     }
   ]

README.md

@@ -58,13 +58,13 @@ compile 'com.google.cloud:google-cloud-bigquery'
 If you are using Gradle without BOM, add this to your dependencies
 
 ```Groovy
-compile 'com.google.cloud:google-cloud-bigquery:2.0.1'
+compile 'com.google.cloud:google-cloud-bigquery:2.1.0'
 ```
 
 If you are using SBT, add this to your dependencies
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-bigquery" % "2.0.1"
+libraryDependencies += "com.google.cloud" % "google-cloud-bigquery" % "2.1.0"
 ```
 
 ## Authentication