feat(docs): enhance flowchart section with detailed explanations and …

…examples

- Added comprehensive definitions for algorithm and flowchart concepts.
- Provided improved descriptions of program and system flowcharts.
- Enhanced flowchart symbol explanations with clear examples.
- Included step-by-step flowchart creation process for common tasks like average calculation and area of a rectangle.
- Detailed programming considerations for computations, decision-making, loops, and predefined processes.
- Added real-world examples and improved readability for better understanding.