message: [doc] fix typos in doc.
diff: @@ -767,7 +767,7 @@ our `orc` Monster, lets create some `Weapon`s: a `Sword` and an `Axe`.
  - // The genearted ObjectBuilder classes offer an easier to use alternative
  + // The generated ObjectBuilder classes offer an easier to use alternative
  // at the cost of requiring some additional reference allocations. If memory
  // usage is critical, or if you'll be working with especially large messages
  // or tables, you should prefer using the generated Builder classes.
  @@ -1238,7 +1238,7 @@ for the `path` field above:
  final vec3Builder = new myGame.Vec3Builder(builder);
  vec3Builder.finish(4.0, 5.0, 6.0);
  vec3Builder.finish(1.0, 2.0, 3.0);
  - final int path = builder.endStructVector(2); // the lenght of the vector
  + final int path = builder.endStructVector(2); // the length of the vector
  // Otherwise, using the ObjectBuilder classes:
  // The dart implementation provides a simple interface for writing vectors
  @@ -1520,7 +1520,7 @@ can serialize the monster itself:
  // Create the monster using the `Monster::create` helper function. This
  // function accepts a `MonsterArgs` struct, which supplies all of the data
  // needed to build a `Monster`. To supply empty/default fields, just use the
  - // Rust built-in `Default::default()` function, as demononstrated below.
  + // Rust built-in `Default::default()` function, as demonstrated below.
  let orc = Monster::create(&mut builder, &MonsterArgs{
  pos: Some(&Vec3::new(1.0f32, 2.0f32, 3.0f32)),
  mana: 150,
  @@ -1663,7 +1663,7 @@ Here is a repetition these lines, to help highlight them more clearly:
  </div>
  <div class="language-c">
  ~~~{.c}
  - // Add union type and data simultanously.
  + // Add union type and data simultaneously.
  ns(Monster_equipped_Weapon_add(B, axe));
  ~~~
  </div>
  @@ -1906,7 +1906,7 @@ like so:
  Now you can write the bytes to a file, send them over the network..
  -**Make sure your file mode (or tranfer protocol) is set to BINARY, not text.**
  +**Make sure your file mode (or transfer protocol) is set to BINARY, not text.**
  If you transfer a FlatBuffer in text mode, the buffer will be corrupted,
  which will lead to hard to find problems when you read the buffer.
  @@ -2207,7 +2207,7 @@ accessors for all non-`deprecated` fields. For example:
  <div class="language-csharp">
  ~~~{.cs}
  // For C#, unlike most other languages support by FlatBuffers, most values (except for
  - // vectors and unions) are available as propreties instead of asccessor methods.
  + // vectors and unions) are available as properties instead of accessor methods.
  var hp = monster.Hp
  var mana = monster.Mana
  var name = monster.Name
  @@ -2258,7 +2258,7 @@ accessors for all non-`deprecated` fields. For example:
  <div class="language-dart">
  ~~~{.dart}
  // For Dart, unlike other languages support by FlatBuffers, most values
  - // are available as propreties instead of asccessor methods.
  + // are available as properties instead of accessor methods.
  var hp = monster.hp;
  var mana = monster.mana;
  var name = monster.name;
  