doc: hint in error message

[prestwich]

Adds a user-facing hint to the NoWasmFound error. A major cause seems to be having a lib.rs instead of a main.rs

Made using web UI. Didn't run linter or anything, sorry 😅

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[cla-bot]

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[rauljordan]

hi @prestwich really appreciate you taking a look at this and opening this PR. Just wondering if you can sign the attached CLA so we can merge this in. Thanks for your time!

[cla-bot]

We require contributors to sign our Contributor License Agreement. In order for us to review and merge your code, please sign the linked documents below to get yourself added. https://na3.docusign.net/Member/PowerFormSigning.aspx?PowerFormId=b15c81cc-b5ea-42a6-9107-3992526f2898&env=na3&acct=6e152afc-6284-44af-a4c1-d8ef291db402&v=2

[prestwich]

In lieu of agreeing to the CLA, I've explicitly licensed the 6 words of my contribution and a comment describing exactly which content is reproduced under that license. Preserving the copyright notice in-line should cover any future licensing questions 👍