message: Update "Directory structure" in toplevel README.
  I don't think it's useful to indent the entire tree, so this removes
  the redundant root. More importantly, it adds the "web" folder. :)
diff: @@ -98,7 +98,9 @@ Many other features have been either prototyped or planned:
  ## Directory structure
  -- `filament`: Filament engine and its supporting libraries and tools
  +This repository not only contains the core Filament engine, but also its supporting libraries
  +and tools.
  +
  - `android`: Android libraries and projects
  - `build`: Custom Gradle tasks for Android builds
  - `filament-android`: Filament library (AAR) for Android
  @@ -108,7 +110,7 @@ Many other features have been either prototyped or planned:
  - `build`: CMake build scripts
  - `docs`: Documentation
  - `math`: Mathematica notebooks used to explore BRDFs, equations, etc.
  - - `filament`: Filament engine
  +- `filament`: Filament rendering engine (minimal dependencies)
  - `ide`: Configuration files for IDEs (CLion, etc.)
  - `ios`: Sample projects for iOS
  - `java`: Java bindings for Filament libraries
  @@ -134,11 +136,12 @@ Many other features have been either prototyped or planned:
  - `filamesh`: Mesh converter
  - `matc`: Material compiler
  - `matinfo` Displays information about materials compiled with `matc`
  - - `mipgen` Generates a series of miplevels from a source image.
  + - `mipgen` Generates a series of miplevels from a source image
  - `normal-blending`: Tool to blend normal maps
  - `roughness-prefilter`: Pre-filters a roughness map from a normal map to reduce aliasing
  - `skygen`: Physically-based sky environment texture generator
  - `specular-color`: Computes the specular color of conductors based on spectral data
  +- `web`: JavaScript bindings, documentation, and samples
  ## Building Filament
  