Rename "column" to "position" #75
Description
When a tab is involved, the next character's column is indeterminant unless we know how tabs are being interpreted, and we don't. So, we'll use the term "position" to refer to a 1-indexed location of a character from the beginning of a line. We'll use the term "index" to refer to a 0-indexed location for a character from the beginning of a line.