Add fuzzy water tank control example with PID comparison

[gomurin0428]

PR description

• Add a water tank control application to the docs

Before

• The only application example was edge detection.

After

• There is a fuzzy water tank control example. There is Fuzzy vs PID comparison plots.

Related issues

• n/a

Checklist

• [ ] Updated/added tests
• [ ] Updated/added docstring (needed only for exported functions)