docs: improve contributing guide

CONTRIBUTING.md

@@ -1,8 +1,14 @@
 A lot of effort has been put into `Faker` to create a useful and handy library.
 There are still a lot of things to be done, so all contributions are welcome!
-If you want to make `Faker` a better, please read the following contribution guide.
+If you want to make `Faker` a better place, please read the following contribution guide.
 
-# Important
+## Before you start
+
+- If you would like to propose a new feature, create an issue first.
+- Bug fixes or locale changes don't need an issue.
+- Issues with precise reproduction steps are a valuable contribution by itself.
+
+## Important
 
 Please make sure that you run `pnpm run preflight` before making a PR to ensure that everything is working from the start.  
 This is a shorthand for running the following scripts in order:
@@ -218,7 +224,7 @@ Not every change needs to be in the migration guide. If it is too long, it becom
 
 - New locales
 - Changes to locale data in existing locales
-- Bugfixes where it's unlikely anyone was relying on the old behavior (eg broken values in locale files)
+- Bugfixes where it's unlikely anyone was relying on the old behavior (e.g. broken values in locale files)
 - New methods and parameters
 - Straightforward method aliases, e.g. where a method or parameter is renamed but the old name still works identically. (Runtime warnings will already guide the user in this case)
 - Changes to locale definition files which only affect usage via `faker.helpers.fake`, e.g. if a definition file is renamed, but the public API for the method stays the same