Fix some formatting of compaction blog post

docs/_posts/2016-01-29-compaction_pri.markdown

@@ -40,7 +40,7 @@ Our default compaction priority **kByCompensatedSize **considers the case. If nu
 Usually people use [compaction filters](https://github.com/facebook/rocksdb/blob/v4.1/include/rocksdb/options.h#L201-L226) to clean up old data to free up space. Picking files to compact may impact space efficiency. We don't yet have a a compaction priority to optimize this case. In some of our use cases, we solved the problem in a different way: we have an external service checking modify time of all SST files. If any of the files is too old, we force the single file to compaction by calling DB::CompactFiles() using the single file. In this way, we can provide a time bound of data passing through compaction filters.
 
 
-In all, there three choices of compaction priority modes optimizing different scenarios. if you have a new use case, we suggest you start with options.compaction_pri=kOldestSmallestSeqFirst (note it is not the default one for backward compatible reason). If you want to further optimize your use case, you can try other two use cases if your use cases apply.
+In all, there three choices of compaction priority modes optimizing different scenarios. if you have a new use case, we suggest you start with `options.compaction_pri=kOldestSmallestSeqFirst` (note it is not the default one for backward compatible reason). If you want to further optimize your use case, you can try other two use cases if your use cases apply.
 
 If you have good ideas about better compaction picker approach, you are welcome to implement and benchmark it. We'll be glad to review and merge your a pull requests.