fix typo in llms.txt (#97)

## 💸 TL;DR
<!-- What's the three sentence summary of purpose of the PR -->
A typo in https://developers.reddit.com/docs/llms-full.txt was reported.
`onModActions` was changed to `onModAction` which is correct

Author: vdikransamarjian

docs/capabilities/server/triggers.mdx

@@ -28,7 +28,7 @@ Event triggers let your app automatically respond to a user's or moderator's act
 - `onPostSpoilerUpdate`
 - `onAppInstall`
 - `onAppUpgrade`
-- `onModActions`
+- `onModAction`
 - `onModMail`
 - `onAutomoderatorFilterPost`
 - `onAutomoderatorFilterComment`

versioned_docs/version-0.12/capabilities/server/triggers.mdx

@@ -28,7 +28,7 @@ Event triggers let your app automatically respond to a user's or moderator's act
 - `onPostSpoilerUpdate`
 - `onAppInstall`
 - `onAppUpgrade`
-- `onModActions`
+- `onModAction`
 - `onModMail`
 - `onAutomoderatorFilterPost`
 - `onAutomoderatorFilterComment`