Add organization profile for omalloc

[Copilot]

The repository lacked organization identity. Added comprehensive profile describing omalloc's focus on memory allocation and management technology.

Changes

• README.md: Organization overview with mission, projects, contribution guidelines, and community standards
• profile/README.md: GitHub organization profile page with vision, core focus areas, and feature highlights

Content

Establishes omalloc as focused on:

• High-performance memory allocators
• Memory analysis and leak detection tools
• Memory safety and optimization best practices
• Open-source collaboration and knowledge sharing

Bilingual (Chinese/English) to match organizational context.

Original prompt

根据本组织介绍一下本组织是做什么的

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