Add config support for build activity indicator position (#30109)
When you edit your code, and Next.js is compiling the application, a compilation indicator appears in the bottom right corner of the page.
In some cases this indicator can be misplaced on the page, for example, when conflicting with a chat launcher. To change its position, open `next.config.js` and set the `buildActivityPosition` in the `devIndicators` object to `bottom-right` (default), `bottom-left`, `top-right` or `top-left`.
I also added the documentation for both `devIndicators.buildActivity` & the new `devIndicators.buildActivityPosition`.
## Feature
- [x] Implements a new feature
- [x] Documentation added