Add utils for working with endianness, more documentation, refactor CMake

Decided to update the docs, as well as adding few new features and small
refactoring.

doc/Features.md

@@ -0,0 +1,29 @@
+# Features
+
+## Implemented features
+
+Currently implemented features:
+
+- Abstraction over input/output
+- Basic data structures (hashmap, queue)
+- Basic algorithms (sorting, swapping, working with heap, partitioning)
+- Geomtric primitives (vectors, matrices, quaternions, rays, boxes)
+- Intersection calculation (ray, boxes, segments, lines, planes, triangles)
+- Unit testing library (for internal usage)
+
+## Planned features
+
+Currently planned features:
+
+- Command-line interface utilities
+- Thread support (thread, mutex, cv, atomics, etc.)
+- Image loading/processing/saving support
+- Polygon rasterization (possibly canvas)
+- UTF8 string support (BMP handling)
+- Font rendering
+- GUI (Windows GUI, X11)
+- Deflate/Inflate implementation
+- Audio loading/processing/saving support
+- FFT/IFFT and complex numbers
+- Basic 2D/3D physics engine (possibly as a separate library?)
+- Configuration support (INI, JSON, Registry)