docs: tune up callbacks

Closes #5285

Author: Foxandxss

src/alert/docs/readme.md

@@ -2,9 +2,8 @@ This directive can be used both to generate alerts from static and dynamic model
 
 ### uib-alert settings
 
-* `close`
-  <small class="badge">$</small>
-  _(Default: `none`)_ -
+* `close()`
+  <small class="badge">$</small> -
   A callback function that gets fired when an `alert` is closed. If the attribute exists, a close button is displayed as well.
 
 * `dismiss-on-timeout`

src/datepicker/docs/readme.md

@@ -13,13 +13,11 @@ The datepicker has 3 modes:
 ### uib-datepicker settings
 
 * `custom-class (date, mode)`
-  <small class="badge">$</small>
-  _(Default: `null`)_ -
+  <small class="badge">$</small> -
   An optional expression to add classes based on passing a date and current mode.
 
 * `date-disabled (date, mode)`
-  <small class="badge">$</small>
-  _(Default: `null`)_ -
+  <small class="badge">$</small> -
   An optional expression to disable visible options based on passing a date and current mode.
 
 * `datepicker-mode`

src/tabs/docs/readme.md

@@ -25,8 +25,7 @@ AngularJS version of the tabs directive.
   Whether tab is currently selected.
 
 * `deselect()`
-  <small class="badge">$</small>
-  _(Default: `null`)_ -
+  <small class="badge">$</small> -
   An optional expression called when tab is deactivated.
 
 * `disable`
@@ -39,8 +38,7 @@ AngularJS version of the tabs directive.
   Heading text.
 
 * `select()`
-  <small class="badge">$</small>
-  _(Default: `null`)_ -
+  <small class="badge">$</small> -
   An optional expression called when tab is activated.
 
 ### Tabset heading