* input and output tests
* input and output types for dfr
* expression converter
* remove deprecated command
* correct expressions
* cargo clippy
* identifier for ls
* cargo clippy
* type for head and tail expression
* modify full cell path if block
* change between lazy and eager
* when expressions
* examples for aggregations
* more examples for agg
* examples for dataframes
* checked examples
* cargo fmt
* lazyframe definition
* expressions and lazy frames
* new alias expression
* more expression commands
* updated to polars main
* more expressions and groupby
* more expressions, fetch and sort-by
* csv reader
* removed open csv
* unique function
* joining functions
* join lazy frames commands with eager commands
* corrected tests
* Update .gitignore
* Update .gitignore
Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>
