Doc theme (#5)

* change docs theme + links + logo

* move mlx intro to landing page

docs/src/index.rst

@@ -1,6 +1,30 @@
 MLX
 ===
 
+MLX is a NumPy-like array framework designed for efficient and flexible
+machine learning on Apple silicon.
+
+The Python API closely follows NumPy with a few exceptions. MLX also has a
+fully featured C++ API which closely follows the Python API.
+
+The main differences between MLX and NumPy are:
+
+ - **Composable function transformations**: MLX has composable function
+   transformations for automatic differentiation, automatic vectorization,
+   and computation graph optimization.
+ - **Lazy computation**: Computations in MLX are lazy. Arrays are only
+   materialized when needed.
+ - **Multi-device**: Operations can run on any of the supported devices (CPU,
+   GPU, ...)
+
+The design of MLX is strongly inspired by frameworks like `PyTorch
+<https://pytorch.org/>`_, `Jax <https://github.com/google/jax>`_, and
+`ArrayFire <https://arrayfire.org/>`_. A noteable difference from these
+frameworks and MLX is the *unified memory model*. Arrays in MLX live in shared
+memory. Operations on MLX arrays can be performed on any of the supported
+device types without performing data copies. Currently supported device types
+are the CPU and GPU.
+
 .. toctree::
    :caption: Install
    :maxdepth: 1