Add onboarding to steward guideline

Author: ksen0

contributor_docs/steward_guidelines.md

@@ -11,6 +11,7 @@ Whether you are new to p5.js contribution, are already active on the p5.js GitHu
   - [Community Care](#community-care)
   - [Areas](#areas)
   - [Becoming a Steward](#becoming-a-steward)
+  - [Getting Started with Stewardship](#getting-started-with-stewardship)
 - [Issues](#issues)
   - [Bug report](#bug-report)
   - [Feature request](#feature-request)
@@ -84,6 +85,12 @@ There are two ways to become a steward:
 
 To remain a steward, you must contribute as a steward to at least 1 of the 2 most recent minor releases (e.g., 2.1.0 or 1.11.0 - when the middle number changes). These are not as frequent as patches (e.g., 2.0.3 to 2.0.4 - when the rightmost number changes), and in practice this means that stewards are expected to be active every 4-6 months or so, supporting other contributors through discussion or code review - not necessarily writing code. To step down from stewardship, you can make a PR to remove yourself from `stewards.yml`. You are always welcome to take a pause and reapply in the future!
 
+### Getting Started with Stewardship
+
+1. Keep this guideline handy as a reference - how to help with new issues, bugs, and features. For example, the "Feature request" section includes tips on how to use the the p5.js [access statement](access.md) as a steward.
+2. When helping to answer technical questions or review, try to apply the Processing Foundation [guideline on answering questions](https://discourse.processing.org/t/guidelines-answering-questions/2145) - these can be especially helpful for giving constructive technical feedback.
+3. Join the [p5.js Discord](https://discord.com/invite/SHQ8dH25r9)  - in the `#contribute-to-p5` you're welcome to ask any questions you have about this process - or suggest how it can be improved!
+
 ## Issues
 
 We encourage most source code contributions to start with an issue, and as such, issues are the place where most of the discussions will take place. The steps to take when reviewing an issue will depend on what kind of issue it is. The repo uses [GitHub issue templates](https://github.com/processing/p5.js/blob/main/.github/ISSUE_TEMPLATE) in order to better organize different kinds of issues and encourage issue authors to provide all relevant information about their problems. The first step in reviewing the issue will often be looking through the filled-out template and determining if you need additional information (e.g., because some fields weren't filled in or the incorrect template was used).