Cleans up elementwise function docstrings (#1559)

* Corrected grammatical error "Array have" to "Array must have"

* abs docstring corrected
- abs input does not need to be numeric, as booleans are accepted

* Fixed expected data types of trigonometric functions

* Fixed expected data types of add
- Add can take `bool` inputs, not just numeric.

* Docstrings corrected for expected data types of complex elementwise functions
- proj expects complex inputs and does not always return the same data type as the original input
- conj expects numeric inputs and does not return booleans
- real, imag take any data type

* Fixed docstrings for floor, ceil, and round
- Round now notes that ties are rounded to the nearest even integer and no longer claims to always return the same data type
- Floor does not always return the same data type
- Ceil does not always return the same data type

* Corrected docstrings for comparison functions and divide
- comparison functions expect any data type
- divide expects floating-point data types

* Corrected docstrings for elementwise exponential and logarithm variants
- log1p, logaddexp, and expm1 docstrings are now more descriptive
- input types corrected in all cases

* Adjustments to `isnan`, `isinf`, and `isfinite` docstrings
- input types corrected
- 'check' changed to 'test'

* Changes to maximum, minimum, positive, and negative docstrings
- Fixed spacing throughout docstrings

* Changes to docstrings of floor_divide, pow, remainder, sign, and signbit

* Corrections to hypot, square, and sqrt docstrings

* usm_narray typo corrected to usm_ndarray

* Tweaks to logaddexp docstring

* Changes to docstrings of hyperbolic trigonmetric functions

* Fixes expected data types in floor and trunc docstrings

Author: ndgrigorian