v0.5.0-beta

Pre-release of hls4ml version v0.5.0.

What's new:

• Streaming IO layer implementations, especially of Convolutional layers, accessed through the config with io_type: io_stream. Scales CNN support to much larger models than previously possible (see paper)
• New documentation and API reference
• Further optimizations for QKeras / quantization aware training. A 'shift' operation is now used for po2 quantizers
• Allow redefinition of weights directory for standalone project compilation