Pyslvs-ui

+ Periodic update.

**Features**:

+ Add four-bar linkage generating function.

**Development**:

+ Pyslvs-UI become a `setup.cfg` only package.
(<https://setuptools.readthedocs.io/en/latest/setuptools.html#setup-cfg-only-projects>)
+ Warning for different kernel version instead of raising error.

+ Periodic update.

**Features**:

+ Add PSO method for optimization.

**Development**:

+ None.

**Features**:

+ Documentation improvement.

**Development**:

+ None.

**Features**:

+ UI improvement. (Menu and functions)
+ Display the callback time of the objective function.
+ Add a function for plotting normalized path.

**Development**:

+ Dropped Qt RCC support.
+ Dropped the support of Python 3.7.
+ Start using `TypedDict` typing.
+ Use `importlib.metadata`.
+ Use assignment expression.
+ Create a hook for PyInstaller.
+ Rename scripts.