chore: update rebar plugins and add exdoc

Author: codeadict

rebar.config

@@ -14,9 +14,11 @@
 ]}.
 
 {project_plugins, [
-    {rebar3_codecov, {git, "https://github.com/esl/rebar3_codecov.git", {ref, "89915c0\n"}}},
-    {rebar3_lint, "~> 4.2"},
-    {erlfmt, "~> 1.7"},
+    {covertool, "~> 2.0"},
+    {erlfmt, "~> 1.8"},
+    {rebar3_ex_doc, "~> 0.2"},
+    {rebar3_hex, "~> 7.1"},
+    {rebar3_lint, "~> 5.0"},
     {rebar3_proper, "~> 0.12"}
 ]}.
 
@@ -135,3 +137,5 @@
         ]}
     ]}
 ]}.
+
+{hex, [{doc, #{provider => ex_doc}}]}.