Plugin Catalog: WASM plugins that are not Go code are not found from GitHub

[mobileskyfi]

spinoff of issue from traefik/plugindemowasm#6

I wrote a Traefik WASM plugin using Grain, originally just try both Grain and Traefik's WASM support. Since it did... I decided to write it up into a demo project here:
https://github.com/tikoci/traefik-wasm-grain

But despite doing have a valid .traefik.yml including working testData per the "pluginwasmdemo" project, the Traefik Plugin Catalog never found the Grain-based WASM plugin. And never got a failure GitHub issue either. Eventually, I found this project which had the clue in scrapper.go with the GitHub query used:
searchQuery = "topic:traefik-plugin language:Go archived:false is:public"

Once I learned how GitHub detects programming languages, and added .gitattributes to GitHub to say the code was Go...Traefik's Catalog found it, and apparently validated it.

As noted in traefik/plugindemowasm#6 , I'm not sure the right solution. But overriding language detection for WASM plugins is not a great long-term solution.

[mloiseleur]

Thanks for your interest in Traefik and this detailed issue.

This example plugin using Grain is now browsed correctly by the bot and so, it appears in the catalog here.

Feel free to re-open this issue or open a new one if we missed something.