docs: iio: adxl345: grammar and formatting cleanups

docs: iio: adxl345: grammar and formatting cleanups

Correct several grammatical errors, typos, and pluralization issues
throughout the ADXL345 documentation.

Key changes include:
- Changing 'generic' to 'general-purpose'
- Correcting 'axis' to 'axes' in multiple tables and descriptions
- Improving phrasing in the device attributes section
- Fixing 'latent' to 'latency' in usage examples
- Sorting the existing event attribute table alphabetically for
  better readability and to establish a clean baseline for future
  additions.

Suggested-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Taha Ed-Dafili <0rayn.dev@gmail.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>