chore: regenerate README (#659)

This PR was generated using Autosynth. 🌈


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

```
2021-08-31 19:52:57,121 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-errorreporting/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-08-31 19:52:58,329 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/ad76469b-3327-4e4b-82c8-4efdced43efb/targets

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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-errorreporting.git",
-        "sha": "8b616e94eb9dfb99b96f2eea1fc48e6dd7c1e610"
+        "sha": "9d4e28ab57cc53c515dfc97aba7e4cbb6bb7eebf"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "31728d872f50e439ded2f67fa8d67955b26a4e35"
+        "sha": "9a238a0623879c3de129a376c6085d4a862f6eb9"
       }
     }
   ]

README.md

@@ -73,12 +73,12 @@ 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-errorreporting'
+implementation 'com.google.cloud:google-cloud-errorreporting'
 ```
 If you are using Gradle without BOM, add this to your dependencies
 
 ```Groovy
-compile 'com.google.cloud:google-cloud-errorreporting:0.122.3-beta'
+implementation 'com.google.cloud:google-cloud-errorreporting:0.122.3-beta'
 ```
 
 If you are using SBT, add this to your dependencies