docs: 对文件格式进行预处理，以免不必要的冲突

Author: Zhicheng WANG

src/cdk/a11y/a11y-module.ts

@@ -14,7 +14,6 @@ import {CdkTrapFocus} from './focus-trap/focus-trap';
 import {HighContrastModeDetector} from './high-contrast-mode/high-contrast-mode-detector';
 import {CdkAriaLive} from './live-announcer/live-announcer';
 
-
 @NgModule({
   imports: [PlatformModule, ObserversModule],
   declarations: [CdkAriaLive, CdkTrapFocus, CdkMonitorFocus],

src/cdk/a11y/aria-describer/aria-describer.ts

@@ -10,7 +10,6 @@ import {DOCUMENT} from '@angular/common';
 import {Inject, Injectable, OnDestroy} from '@angular/core';
 import {addAriaReferencedId, getAriaReferenceIds, removeAriaReferencedId} from './aria-reference';
 
-
 /**
  * Interface used to register message elements and keep a count of how many registrations have
  * the same message and the reference to the message element used for the `aria-describedby`.

src/cdk/a11y/focus-monitor/focus-monitor.ts

@@ -25,17 +25,15 @@ import {coerceElement} from '@angular/cdk/coercion';
 import {DOCUMENT} from '@angular/common';
 import {isFakeMousedownFromScreenReader} from '../fake-mousedown';
 
-
 // This is the value used by AngularJS Material. Through trial and error (on iPhone 6S) they found
 // that a value of around 650ms seems appropriate.
 export const TOUCH_BUFFER_MS = 650;
 
-
 export type FocusOrigin = 'touch' | 'mouse' | 'keyboard' | 'program' | null;
 
 /**
  * Corresponds to the options that can be passed to the native `focus` event.
- * via https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/focus
+ * via <https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/focus>
  */
 export interface FocusOptions {
   /** Whether the browser should scroll to the element when it is focused. */
@@ -81,7 +79,6 @@ const captureEventListenerOptions = normalizePassiveListenerOptions({
   capture: true
 });
 
-
 /** Monitors mouse and keyboard events to determine the cause of focus events. */
 @Injectable({providedIn: 'root'})
 export class FocusMonitor implements OnDestroy {
@@ -580,7 +577,6 @@ function getTarget(event: Event): HTMLElement|null {
   return (event.composedPath ? event.composedPath()[0] : event.target) as HTMLElement | null;
 }
 
-
 /**
  * Directive that determines how a particular element was focused (via keyboard, mouse, touch, or
  * programmatically) and adds corresponding classes to the element.

src/cdk/a11y/focus-trap/focus-trap.ts

@@ -24,7 +24,6 @@ import {
 import {take} from 'rxjs/operators';
 import {InteractivityChecker} from '../interactivity-checker/interactivity-checker';
 
-
 /**
  * Class that allows for trapping focus within a DOM element.
  *

src/cdk/a11y/high-contrast-mode/high-contrast-mode-detector.ts

@@ -10,7 +10,6 @@ import {Platform} from '@angular/cdk/platform';
 import {DOCUMENT} from '@angular/common';
 import {Inject, Injectable} from '@angular/core';
 
-
 /** Set of possible high-contrast mode backgrounds. */
 export const enum HighContrastMode {
   NONE,

src/cdk/a11y/live-announcer/live-announcer.ts

@@ -26,7 +26,6 @@ import {
   LIVE_ANNOUNCER_DEFAULT_OPTIONS,
 } from './live-announcer-tokens';
 
-
 @Injectable({providedIn: 'root'})
 export class LiveAnnouncer implements OnDestroy {
   private _liveElement: HTMLElement;
@@ -172,7 +171,6 @@ export class LiveAnnouncer implements OnDestroy {
 
 }
 
-
 /**
  * A directive that works similarly to aria-live, but uses the LiveAnnouncer to ensure compatibility
  * with a wider range of browsers and screen readers.

src/cdk/accordion/accordion-module.ts

@@ -10,7 +10,6 @@ import {NgModule} from '@angular/core';
 import {CdkAccordion} from './accordion';
 import {CdkAccordionItem} from './accordion-item';
 
-
 @NgModule({
   exports: [CdkAccordion, CdkAccordionItem],
   declarations: [CdkAccordion, CdkAccordionItem],

src/cdk/bidi/bidi-module.ts

@@ -9,7 +9,6 @@
 import {NgModule} from '@angular/core';
 import {Dir} from './dir';
 
-
 @NgModule({
   exports: [Dir],
   declarations: [Dir],

src/cdk/bidi/dir-document-token.ts

@@ -9,7 +9,6 @@
 import {DOCUMENT} from '@angular/common';
 import {inject, InjectionToken} from '@angular/core';
 
-
 /**
  * Injection token used to inject the document into Directionality.
  * This is used so that the value can be faked in tests.

src/cdk/bidi/directionality.ts

@@ -9,10 +9,8 @@
 import {EventEmitter, Inject, Injectable, Optional, OnDestroy} from '@angular/core';
 import {DIR_DOCUMENT} from './dir-document-token';
 
-
 export type Direction = 'ltr' | 'rtl';
 
-
 /**
  * The directionality (LTR / RTL) context for the application (or a subtree of it).
  * Exposes the current direction and a stream of direction changes.