Add clj-kondo and fix most linting warnings

Author: Deraen

.clj-kondo/config.edn

@@ -0,0 +1,6 @@
+{;;:skip-comments true
+ :lint-as {potemkin/def-derived-map clojure.core/defrecord}
+ :linters {:if {:level :off}
+           :unused-binding {:level :off}
+           :unused-referred-var {:exclude {clojure.test [deftest testing is are]
+                                           cljs.test [deftest testing is are]}}}}

Justfile

@@ -0,0 +1,10 @@
+help:
+    @just --list
+
+# Initializes lint
+init-lint:
+    clj-kondo --lint $(lein classpath)
+
+# Lints the project
+lint:
+    ./lint.sh