typeahead: add autocomplete="off" to the host

[pkozlowski-opensource]

An input field on which we are setting a typeahead should have those attributes added automatically to the host:

• autocomplete="off"
• autocapitalize="off"
• autocorrect="off"

[pkozlowski-opensource]

Changes to be done in:

• host of the typeahead:

  ng-bootstrap/src/typeahead/typeahead.ts

  Lines 42 to 48 in dc4962d

  	host: {
  	'(blur)': 'onTouched()',
  	'[class.open]': '_windowRef !== null',
  	'(document:click)': '_closePopup()',
  	'(input)': 'onChange($event.target.value)',
  	'(keydown)': '_handleKeyDown($event)'
  	},

• mandatory tests to be added in https://github.com/ng-bootstrap/ng-bootstrap/blob/master/src/typeahead/typeahead.spec.ts

[jnizet]

BTW, I really appreciate that you're encouraging external contributors like you're doing by filing issues and tagging them with the effort tag. It probably took you longer to file the issue than to just fix it in the first place, but it's a great opportunity for me to learn and be useful at the same time. 👍

[pkozlowski-opensource]

BTW, I really appreciate that you're encouraging external contributors like you're doing by filing issues and tagging them with the effort tag

Sure, we definitively want to grow a pool of contributors. So thnx once again for stepping in and helping out!