README: Write development section

Author: kj4ezj

README.md

@@ -17,6 +17,7 @@ You can see it live at [https://stake.eosnetwork.com](https://stake.eosnetwork.c
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+1. [Development](#development)
 1. [See Also](#see-also)
 
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@@ -26,6 +27,12 @@ You can see it live at [https://stake.eosnetwork.com](https://stake.eosnetwork.c
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+## Development
+Start here to build this project or to contribute to this repo.
+
+> [!NOTE]
+> The source of truth for the version of nodeJS this project supports is the [`.nvmrc`](./.nvmrc) file. Backward- or forward-compatibility with other versions of `node` is made on a best-effort basis, but is not guaranteed.
+
 ## See Also
 More resources.
 - [aws-cloudwatch-alarm-handler](https://github.com/eosnetworkfoundation/aws-cloudwatch-alarm-handler) lambda