docs: add solutions directory for find-solver skill output

Author: GiggleLiu

docs/solutions/README.md

@@ -0,0 +1,18 @@
+# Solution Guides
+
+Each file in this directory is a step-by-step guide for solving a specific
+real-world problem using the `pred` CLI.
+
+Generated interactively via the `/find-solver` skill.
+
+## Naming Convention
+
+`<problem>-via-<model>-<solver>.md`
+
+- `<problem>`: short description of the real-world problem (kebab-case)
+- `<model>`: the library model used (e.g., `MIS`, `QUBO`)
+- `<solver>`: the solver target (e.g., `ILP`, `brute-force`, `gurobi`)
+
+## Example
+
+`task-scheduling-via-MultiprocessorScheduling-ILP.md`