Add constant function (#72)
* Added constant function
* Changed constant function description
* Fixed a typo in tests
* Changed constant function name to identity
* Revert "Changed constant function name to identity"
This reverts commit e2bfdb2efaae85c551b7a125bd62391034ddd4bc.
* Fixed wrong description on constant function documentation
* Some coding style fixes
* Update docs/functions/constant.md
Co-Authored-By: fnandot <5954976+fnandot@users.noreply.github.com>
* Update docs/functions/constant.md
Co-Authored-By: fnandot <5954976+fnandot@users.noreply.github.com>
