docs(common): migrate @whatItDoes tags to the description (#23062)

We get the overview for the doc by splitting off the first
paragraph.

PR Close #23062

packages/common/src/pipes/async_pipe.ts

@@ -42,8 +42,10 @@ const _observableStrategy = new ObservableStrategy();
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Unwraps a value from an asynchronous primitive.
  * @description
+ *
+ * Unwraps a value from an asynchronous primitive.
+ *
  * The `async` pipe subscribes to an `Observable` or `Promise` and returns the latest value it has
  * emitted. When a new value is emitted, the `async` pipe marks the component to be checked for
  * changes. When the component gets destroyed, the `async` pipe unsubscribes automatically to avoid

packages/common/src/pipes/date_pipe.ts

@@ -13,9 +13,10 @@ import {invalidPipeArgumentError} from './invalid_pipe_argument_error';
 // clang-format off
 /**
  * @ngModule CommonModule
- * @whatItDoes Uses the function {@link formatDate} to format a date according to locale rules.
  * @description
  *
+ * Uses the function {@link formatDate} to format a date according to locale rules.
+ *
  * Where:
  * - `value` is a date object or a number (milliseconds since UTC epoch) or an ISO string
  * (https://www.w3.org/TR/NOTE-datetime).

packages/common/src/pipes/deprecated/date_pipe.ts

@@ -13,9 +13,10 @@ import {DateFormatter} from './intl';
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Formats a date according to locale rules.
  * @description
  *
+ * Formats a date according to locale rules.
+ *
  * Where:
  * - `expression` is a date object or a number (milliseconds since UTC epoch) or an ISO string
  * (https://www.w3.org/TR/NOTE-datetime).

packages/common/src/pipes/deprecated/number_pipe.ts

@@ -61,7 +61,6 @@ function formatNumber(
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Formats a number according to locale rules.
  *
  * Formats a number as text. Group sizing and separator and other locale-specific
  * configurations are based on the active locale.
@@ -97,11 +96,10 @@ export class DeprecatedDecimalPipe implements PipeTransform {
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Formats a number as a percentage according to locale rules.
  *
  * @description
  *
- * Formats a number as percentage.
+ * Formats a number as percentage according to locale rules.
  *
  * - `digitInfo` See {@link DecimalPipe} for detailed description.
  *
@@ -126,9 +124,10 @@ export class DeprecatedPercentPipe implements PipeTransform {
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Formats a number as currency using locale rules.
  * @description
  *
+ * Formats a number as currency using locale rules.
+ *
  * Use `currency` to format a number as currency.
  *
  * - `currencyCode` is the [ISO 4217](https://en.wikipedia.org/wiki/ISO_4217) currency code, such

packages/common/src/pipes/i18n_plural_pipe.ts

@@ -14,9 +14,10 @@ const _INTERPOLATION_REGEXP: RegExp = /#/g;
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Maps a value to a string that pluralizes the value according to locale rules.
  * @description
  *
+ * Maps a value to a string that pluralizes the value according to locale rules.
+ *
  *  Where:
  *  - `expression` is a number.
  *  - `mapping` is an object that mimics the ICU format, see

packages/common/src/pipes/i18n_select_pipe.ts

@@ -11,9 +11,10 @@ import {invalidPipeArgumentError} from './invalid_pipe_argument_error';
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Generic selector that displays the string that matches the current value.
  * @description
  *
+ * Generic selector that displays the string that matches the current value.
+ *
  *  Where `mapping` is an object that indicates the text that should be displayed
  *  for different values of the provided `expression`.
  *  If none of the keys of the mapping match the value of the `expression`, then the content

packages/common/src/pipes/json_pipe.ts

@@ -10,7 +10,6 @@ import {Pipe, PipeTransform} from '@angular/core';
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Converts value into JSON string.
  * @description
  *
  * Converts value into string using `JSON.stringify`. Useful for debugging.

packages/common/src/pipes/number_pipe.ts

@@ -13,9 +13,10 @@ import {invalidPipeArgumentError} from './invalid_pipe_argument_error';
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Uses the function {@link formatNumber} to format a number according to locale rules.
  * @description
  *
+ * Uses the function {@link formatNumber} to format a number according to locale rules.
+ *
  * Formats a number as text. Group sizing and separator and other locale-specific
  * configurations are based on the locale.
  *
@@ -55,11 +56,10 @@ export class DecimalPipe implements PipeTransform {
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Uses the function {@link formatPercent} to format a number as a percentage according
- * to locale rules.
  * @description
  *
- * Formats a number as percentage.
+ * Uses the function {@link formatPercent} to format a number as a percentage according
+ * to locale rules.
  *
  * Where:
  * - `value` is a number.
@@ -93,11 +93,10 @@ export class PercentPipe implements PipeTransform {
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Uses the functions {@link getCurrencySymbol} and {@link formatCurrency} to format a
- * number as currency using locale rules.
  * @description
  *
- * Use `currency` to format a number as currency.
+ * Uses the functions {@link getCurrencySymbol} and {@link formatCurrency} to format a
+ * number as currency using locale rules.
  *
  * Where:
  * - `value` is a number.

packages/common/src/pipes/slice_pipe.ts

@@ -11,9 +11,10 @@ import {invalidPipeArgumentError} from './invalid_pipe_argument_error';
 
 /**
  * @ngModule CommonModule
- * @whatItDoes Creates a new List or String containing a subset (slice) of the elements.
  * @description
  *
+ * Creates a new List or String containing a subset (slice) of the elements.
+ *
  * Where the input expression is a `List` or `String`, and:
  * - `start`: The starting index of the subset to return.
  *   - **a positive integer**: return the item at `start` index and all items after