restructure docs

Author: blackopsrepl

content/en/docs/_index.md

@@ -7,6 +7,7 @@ menu: {main: {weight: 20}}
 Welcome to the SolverForge documentation. Choose a section to get started:
 
 - **[Overview](overview.md)** - Project Overview and roadmap
+- **[Concepts](concepts/)** - Introduction to PlanningAI
 - **[Getting Started](getting-started/)** — Quickstart guides and tutorials (legacy Python examples)
 - **[Rust Solver](solverforge/)** — Rust-based constraint solver with WASM modules and HTTP communication
 - **[Python Solver](solverforge-legacy/)** — Technical documentation for the Python constraint solver

…cs/solverforge-legacy/concepts/_index.md content/en/docs/concepts/_index.mdcontent/en/docs/solverforge-legacy/concepts/_index.md renamed to content/en/docs/concepts/_index.md content/en/docs/solverforge-legacy/concepts/_index.md renamed to content/en/docs/concepts/_index.md

@@ -1,7 +1,7 @@
 ---
 title: "Concepts"
 linkTitle: "Concepts"
-weight: 10
+weight: 2
 tags: [concepts, python]
 description: >
   Understand the fundamental concepts of planning optimization and constraint solving.