fix: update language field in lab 01 modify search

[Awlie]

Just stumbled across this as I was following the learn path.

This was a fix for me, also somebody else had this issue, see #24

closes #24

[Awlie]

I checked the instructions again, looks like i did it wrong, as search isn't supposed to be active on language, sorry https://github.com/MicrosoftLearning/mslearn-knowledge-mining/blob/main/Instructions/Exercises/01-azure-search.md#index-the-documents