Add myflames to DBA Toolkits

## Summary Adds [myflames](https://github.com/vgrippa/myflames) to the **Toolkits** section of `list-dba.md`. myflames is a stdlib-only Python tool (Python 3.7+, no external dependencies) that visualizes MariaDB `ANALYZE FORMAT=JSON` and MySQL `EXPLAIN ANALYZE FORMAT=JSON` output as interactive SVG flame graphs, bar charts, treemaps, and Visual Explain–style diagrams. Every view includes a query analysis panel that flags full table scans, filesorts, hash joins, BNL buffers, and temp tables, with concrete tuning suggestions. - **MariaDB support**: YES — works with MariaDB 10.11+ / 11.4+ via `ANALYZE FORMAT=JSON`. The parser auto-detects MariaDB vs MySQL output and normalizes MariaDB's `query_block/nested_loop/table` structure into a unified plan tree. - **License**: [CDDL-1.0](https://github.com/vgrippa/myflames/blob/master/LICENSE) - **Language**: Python Also adds my name to `CONTRIBUTORS.md` per the contributing guidelines.