Update text/0081-truncate.md

Co-authored-by: Lei Zhao <[email protected]>

Author: longfangsong

text/0081-truncate.md

@@ -44,7 +44,7 @@ There are several steps to follow when doing truncate:
 
 ### 1. Wait all committed raft log are applied
 
-We can just polling each region's `RegionInfo` in a method similar with [`Debugger::region_info`](https://github.com/tikv/tikv/blob/789c99666f2f9faaa6c6e5b021ac0cf7a76ae24e/src/server/debug.rs#L188) does, and wait for `commit_index` to be equal to `apply_index`.
+We can just polling each region's `RegionInfo` in a method similar with [`Debugger::region_info`](https://github.com/tikv/tikv/blob/789c99666f2f9faaa6c6e5b021ac0cf7a76ae24e/src/server/debug.rs#L188) does, and wait for `apply_index` to be equal to `commit_index`.
 
 ### 2. Clean WriteCF and DefaultCF