recommend GitHub discussions for help (#2152)

Author: mbostock

Diff for: docs/community.md

@@ -14,7 +14,7 @@ And of course, follow us on [Observable](https://observablehq.com/@observablehq?
 
 ## Getting help
 
-We recommend asking for help on the [Observable forum](https://talk.observablehq.com/c/help/6). Or if you prefer chat, join the [Observable community Slack](https://observablehq.com/slack/join).
+We recommend asking for help on [GitHub discussions](https://github.com/observablehq/plot/discussions).
 
 We encourage you to share your work, no matter how messy, on [Observable](https://observablehq.com). Sharing live code is the easiest way to let people see what you see, and to debug your problem. Strive for a [minimal, reproducible example](https://stackoverflow.com/help/minimal-reproducible-example) — it helps people hone in on your problem more quickly.
 
@@ -35,7 +35,9 @@ We’d love for you to join the community! Here are some ways to participate:
 
 * Upvote 👍 or comment on [GitHub issues](https://github.com/observablehq/plot/issues). We’d love your input on what to build next. If your desired feature isn’t already there, or if you’ve found a bug, file an issue and tell us about it.
 
-* Answer questions or participate in discussions on the [Observable forum](https://talk.observablehq.com/) and the [Observable community Slack](https://observablehq.com/slack/join). You’ll help others, and might learn something yourself, too.
+* Answer questions or participate in discussions on [GitHub](https://github.com/observablehq/plot/discussions). You’ll help others, and might learn something yourself, too.
+
+* Join the [Observable community Slack](https://observablehq.com/slack/join) to meet others using Plot.
 
 * Open a pull request! Read our [guide to contributing](https://github.com/observablehq/plot/blob/main/CONTRIBUTING.md).
 

Diff for: docs/why-plot.md

@@ -163,7 +163,7 @@ We’ve long said that *D3 makes things possible, not necessarily easy.* And tha
 **Plot’s goal is to make the easy things easy, and fast, and then some.**
 
 :::tip
-Whether or not Plot succeeds at this goal is up to you — so we’d love [your feedback](https://talk.observablehq.com/c/site-feedback/3) on what you find easy or hard to do with Plot. And we encourage you to [ask for help](https://talk.observablehq.com/c/help/6) when you get stuck. We learn a lot from helping!
+Whether or not Plot succeeds at this goal is up to you — so we’d love [your feedback](https://github.com/observablehq/plot/discussions/new/choose) on what you find easy or hard to do with Plot. And we encourage you to [ask for help](https://github.com/observablehq/plot/discussions/categories/q-a) when you get stuck. We learn a lot from helping!
 :::
 
 Since Plot and D3 have different goals, they make different trade-offs. Plot is more efficient: you can make charts quickly. But it is also necessarily less expressive: bespoke visualizations with extensive animation and interaction, advanced techniques like force-directed graph layout, or even developing your own charting library, are better done with D3’s low-level API.