Fix markdown lint

Author: josevalim

.markdownlint.jsonc

@@ -17,6 +17,8 @@
   "MD014": false,
   // Multiple headings with the same content. That's fine.
   "MD024": false,
+  // Some headers finish with ! because it refers to a function name
+  "MD026": false,
   // Allow empty line between block quotes. Used by contiguous admonition blocks.
   "MD028": false,
   // Allowed HTML inline elements.

lib/elixir/pages/references/naming-conventions.md

@@ -129,9 +129,9 @@ In other words, functions using the word "size" in its name will take the same a
 
 When you see the functions `get`, `fetch`, and `fetch!` for key-value data structures, you can expect the following behaviours:
 
-- `get` returns a default value (which itself defaults to `nil`) if the key is not present, or returns the requested value.
-- `fetch` returns `:error` if the key is not present, or returns `{:ok, value}` if it is.
-- `fetch!` *raises* if the key is not present, or returns the requested value.
+  * `get` returns a default value (which itself defaults to `nil`) if the key is not present, or returns the requested value.
+  * `fetch` returns `:error` if the key is not present, or returns `{:ok, value}` if it is.
+  * `fetch!` *raises* if the key is not present, or returns the requested value.
 
 Examples: `Map.get/2`, `Map.fetch/2`, `Map.fetch!/2`, `Keyword.get/2`, `Keyword.fetch/2`, `Keyword.fetch!/2`