chore: enable eslint rule to detect floating promises (#31)

A "floating" Promise is one that is created without any code set up to
handle any errors it might throw. Floating Promises can cause several
issues, such as improperly sequenced operations, ignored Promise
rejections, and more.

Author: skyrpex

eslint.config.mjs

@@ -20,6 +20,11 @@ export default tseslint.config(
 			"@typescript-eslint/no-explicit-any": "off",
 			// Covered by @typescript-eslint/no-floating-promises.
 			"@typescript-eslint/require-await": "warn",
+			// Customize @typescript-eslint/no-floating-promises.
+			"@typescript-eslint/no-floating-promises": [
+				"warn",
+				{ checkThenables: true },
+			],
 		},
 	},
 	{