rename of entries fields to get only singular field names

entries/xz_utils.md

@@ -3,7 +3,7 @@
 - Home: https://tukaani.org/xz/
 - Media: https://en.wikipedia.org/wiki/XZ_Utils
 - State: mature
-- Keywords: library
+- Keyword: library
 - Code repository: https://git.tukaani.org/xz.git (https://git.tukaani.org/?p=xz.git)
 - Code language: C
 - Code license: Custom (see file Copying, liblzma is public domain)
@@ -15,4 +15,4 @@ Supersedes [LZMA Utils](https://tukaani.org/lzma/)
 
 ## Building
 
-- Build instructions: manual (see instructions in source folder windows)
+- Build instruction: manual (see instructions in source folder windows)