feat: support column aligment in tables

Hi there. It would be nice to use standard column aligment in markdown tables, e.g.: aligning Col 2 below to the right: ``` | Col 1 | Loooooooooooong Col 2 | |---|---:| | A | 1.16x | | B* | 1.21x | | C | 1.30x | ``` Here's github rendering it: | Col 1 | Loooooooooong Col 2 | |---|---:| | A | 1.16x | | B* | 1.21x | | C | 1.30x | But presenterm keeps everything to the left. Thank you!