chore: regenerate README (#361)

This PR was generated using Autosynth. 🌈


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

```
2020-12-10 22:54:45,949 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-logging/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2020-12-10 22:54:46,824 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/50ece71b-c5c5-4e94-b8ec-1b0fbb40c304/targets

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

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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-logging.git",
-        "sha": "729b650ff6a5f5022e5e5a32b0ef7b2c1642858f"
+        "sha": "b07358192b76093d8814338bd21b48a3b1e5c073"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "352f25621c28d2fa0784984ea0ed5ea697aa1525"
+        "sha": "996775eca5fd934edac3c2ae34b80ff0395b1717"
       }
     }
   ]

README.md

@@ -39,7 +39,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-logging</artifactId>
-  <version>2.0.2-SNAPSHOT</version>
+  <version>2.1.0</version>
 </dependency>
 
 ```