- update README.md

Author: dirkarnez

README.md

@@ -30,5 +30,5 @@ staticserver
 - ```{{index . 0}}{{index . 1}}{{index . 2}}....```
 
 ### Warning(s)
-- The mime-type in Windows registry may be modified by other software causing wrong Content-Type in response, see issue(s)
+- The mime-type in Windows registry may be modified by other software causing wrong `Content-Type` in response, see issue(s)
   - https://github.com/golang/go/issues/32350