[Le #142] Minor Grammar Errors

[stanislowskij]

⚠️ Imported from legacy repository. This issue is a duplicate of Clojure-Intro-Course/babel-legacy#142.

The error for key duplication currently reads "You have duplicated the key 1, you cannot use the same key in a hashmap twice." This is grammatically incorrect; the comma should be a semicolon.

Additionally, argument type errors have slightly awkward wording: "The second argument of (map {} map) was expected to be a sequence but is a function map instead." would possibly read more clearly if it said the function map.