message: chore: fix grammar in core/observer/index.js comments
diff: @@ -37,7 +37,7 @@ export function toggleObserving (value: boolean) {
  export class Observer {
  value: any;
  dep: Dep;
  - vmCount: number; // number of vms that has this object as root $data
  + vmCount: number; // number of vms that have this object as root $data
  constructor (value: any) {
  this.value = value
  @@ -57,7 +57,7 @@ export class Observer {
  }
  /**
  - * Walk through each property and convert them into
  + * Walk through all properties and convert them into
  * getter/setters. This method should only be called when
  * value type is Object.
  */
  @@ -81,7 +81,7 @@ export class Observer {
  // helpers
  /**
  - * Augment an target Object or Array by intercepting
  + * Augment a target Object or Array by intercepting
  * the prototype chain using __proto__
  */
  function protoAugment (target, src: Object) {
  @@ -91,7 +91,7 @@ function protoAugment (target, src: Object) {
  }
  /**
  - * Augment an target Object or Array by defining
  + * Augment a target Object or Array by defining
  * hidden properties.
  */
  /* istanbul ignore next */
  