Add KLlama enterprise roadmap document

Outlines the path to making KLlama the #1 choice for multiplatform
LLM inference, competing with jlama while offering unique KMP capabilities.

Key phases:
- Performance: mmap loading, quantized kernels, SIMD, KV-cache
- Developer Experience: Chat API, streaming Flow, templates, tools
- Model Support: Mistral, Phi, Gemma, Qwen, MoE architectures
- Platform Acceleration: Metal, WebGPU, NNAPI
- Distribution: Maven Central, CocoaPods, npm, documentation

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: michalharakal