Add Quick MATLAB Example section to quick_start.rst

[djkees]

Summary

Adds a "Quick MATLAB Example" section to docs/source/quick_start.rst, mirroring the existing "Quick Python Example" section for MATLAB users.

djkees#161

Changes

• docs/source/quick_start.rst: new "Quick MATLAB Example" section, split into "One-Time Setup" (installing Python, installing cea via python -m pip install cea, finding the Python path) and "Every MATLAB Session" (pyenv + importing cea/cea.matlab), followed by a "Solving a Problem" walkthrough that runs cea.matlab.eq_solve on the same stoichiometric H2/O2 HP combustion case as the Python example.
• Prerequisites section updated to mention the MATLAB binding needs no prior Python experience.
• Written for a MATLAB-only reader with no Python/conda/compiler background: every step is copy/paste, including things like opening a Command Prompt window and checking "Add python.exe to PATH" during the Python installer.
• Recommends the plain PyPI install path (pip install cea) rather than building from source, since that avoids needing a compiler/CMake/conda entirely for MATLAB users who just want to call cea from MATLAB.
• Includes a troubleshooting note for MATLAB's pyenv Python-version compatibility (MATLAB only supports a limited range of Python versions per release), linking to MathWorks' compatibility table.

Testing

• The full one-time-setup + every-session + solve walkthrough was run live end-to-end in MATLAB (R2026a) against a freshly built cea install, confirming each step and command as written.
• The eq_solve call's numeric result (Adiabatic flame temperature: 3074.5 K) was independently cross-checked against the existing Python quickstart's own EqSolver/Mixture low-level API for the same H2/O2 inputs, which produced the identical 3074.5 K.

Compatibility / Numerical behavior

• No expected changes to numerical results

Drafted with Claude's assistance

• Verified live in the user's own MATLAB session (R2026a) — every command in the doc was run and its output pasted back before being written into the doc.
• Cross-checked the example's numeric result against the existing Python quickstart example's own solve path for the same inputs (both produce 3074.5 K).