`quick_start.md`: Add quick start guide (#8469)

docs/mkdocs.yml

@@ -56,6 +56,7 @@ markdown_extensions:
 
 nav:
   - Overview: "index.md"
+  - Quick Start: "quick_start.md"
   - Tutorial: "tutorial.md"
   - Compiler (flatc): 
     - Building: "building.md"

docs/source/quick_start.md

@@ -0,0 +1,90 @@
+# Quick Start
+
+This will quickly go over the parts of using FlatBuffers to serialize some data.
+See the [Tutorial](tutorial.md) for a more in depth guide.
+
+1. **Build the compiler for FlatBuffers ([`flatc`](flatc.md))**
+
+    ```sh
+    cmake -G "Unix Makefiles"
+    make -j
+    ```
+
+2. **Define your FlatBuffer [schema](schema.md) (`.fbs`)**
+
+    ```c title="monster.fbs" linenums="1"
+    table Monster {
+      name:string;
+      health:int;
+    }
+
+    root_type Monster;
+    ```
+
+    See [monster.fbs](https://github.com/google/flatbuffers/blob/master/samples/monster.fbs)
+    for an complete example.
+
+3. **Generate code for your language(s)**
+
+    Use the `flatc` compiler to take your schema and generate language-specific
+    code:
+
+    ```sh
+    ./flatc --cpp --rust mosnter.fbs
+    ```
+
+    Which generates `monster_generated.h` and `monster_generated.rs` files.
+
+4. **Serialize data**
+
+    Use the generated code files, as well as the `FlatBufferBuilder` to construct
+    your serialized buffer.
+
+    ```c++ title="my_monster_factory.cc" linenums="1"
+    #include "flatbuffers.h"
+    #include "monster_generated.h"
+
+    int main() { 
+      // Used to build the flatbuffer
+      FlatBufferBuilder builder;
+
+      // Auto-generated function emitted from `flatc` and the input 
+      // `monster.fbs` schema.
+      auto monster = CreateMonsterDirect(builder, "Abominable Snowman", 100);
+
+      // Finalize the buffer.
+      builder.Finish(monster);
+    }
+    ```
+
+    See complete [C++ Example](https://github.com/google/flatbuffers/blob/master/samples/sample_binary.cpp#L24-L56).
+
+5.  **Transmit/Store the serialized FlatBuffer**
+  
+    Use your serialized buffer however you want. Send it to someone, save if for
+    later, etc...
+
+    ```c++ title="my_monster_factory.cc" linenums="13"
+    // Get a pointer to the flatbuffer.
+    const uint8_t* flatbuffer = builder.GetBufferPointer();
+    ```
+
+6.  **Read the data**
+
+    Use the generated accessors to read the data from the serialized buffer.
+
+    It doesn't need to be the same language, or even schema version (see 
+    [Evolving](evolution.md)), FlatBuffers ensures the data is readable across
+    languages and schema versions. 
+    
+    ```c++ title="my_monster_factory.cc" linenums="15"
+    // Get a view of the root monster from the flatbuffer.
+    const Monster snowman = GetMonster(flatbuffer);
+
+    // Access the monster's fields directly.
+    ASSERT_EQ(snowman.name(), "Abominable Snowman");
+    ASSERT_EQ(snowman.health(), 100);
+    ```    
+    
+    See [`Rust` examples](https://github.com/google/flatbuffers/blob/master/samples/sample_binary.rs#L92-L106)
+    for reading the data written by `C++`.