chore: regenerate README (#1548)

This PR was generated using Autosynth. 🌈


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

```
2021-08-29 16:16:46,823 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-bigquery/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-08-29 16:16:48,027 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/ce17b2cb-d7f7-462d-8c2a-e609ff1a043f/targets

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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-bigquery.git",
-        "sha": "336a861e2e0a80bfc43a96844219ec2d0493a967"
+        "sha": "c00e6b663b983e6ec030323d9da6829416065be5"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "31728d872f50e439ded2f67fa8d67955b26a4e35"
+        "sha": "e770c12f2a9a5f84566fe04b16a4ceec1c8c109b"
       }
     }
   ]

README.md

@@ -53,12 +53,12 @@ If you are using Gradle 5.x or later, add this to your dependencies
 ```Groovy
 implementation platform('com.google.cloud:libraries-bom:22.0.0')
 
-compile 'com.google.cloud:google-cloud-bigquery'
+implementation '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:2.1.4'
+implementation 'com.google.cloud:google-cloud-bigquery:2.1.4'
 ```
 
 If you are using SBT, add this to your dependencies