[docs] Remove Discord mention from docs#21855

mapache-salvaje merged 6 commits intomui:mastermui/mui-x:masterfrom

mapache-salvaje:feature/dx-177-remove-all-remaining-mentions-of-discord-from-the-docsmapache-salvaje/mui-x:feature/dx-177-remove-all-remaining-mentions-of-discord-from-the-docsCopy head branch name to clipboard