docs: use the apache domain for website link (#610)

.github/ISSUE_TEMPLATE/general_question.md

@@ -10,4 +10,4 @@ Before asking a question, make sure you have:
 
 - Searched open and closed [GitHub issues](https://github.com/XiaoMi/pegasus/issues)
 - Read the documentation:
-  - [Pegasus Doc](https://pegasus-kv.github.io)
+  - [Pegasus Doc](https://pegasus.apache.org)

README.md

@@ -3,7 +3,7 @@
 [pegasus-rocksdb]: https://github.com/xiaomi/pegasus-rocksdb
 [facebook-rocksdb]: https://github.com/facebook/rocksdb
 [hbase]: https://hbase.apache.org/
-[website]: https://pegasus-kv.github.io
+[website]: https://pegasus.apache.org
 
 ![pegasus-logo](docs/media-img/pegasus-logo.png)