Plugins: Fix minor spelling mistake
@@ -207,7 +207,7 @@ copied by the `spec` plugin just before):
- [path](path/) by checking files on file system
- [type](type/) using run-time type checking (CORBA types/)
- [enum](enum/) compares the keyvalue against a list of valid values
-- [mathcheck](mathcheck/) by mathematical expressions using keysvalues as operands
+- [mathcheck](mathcheck/) by mathematical expressions using key values as operands
- [conditionals](conditionals/) by using if-then-else like statements
- [required](required/) rejects non-required keys
- [date](date/) validates date and time data
