Add usage_column and usage_width

[A4-Tacks]

Adjustable starting column and width of text is a good idea

Examples

Default:

Usage: pegview [-c] [-i NAME].. [-I NAME].. [-u] [-L] [--share-width STYLE] [-e] [-r] [-w] [-s] [-S SRC] [-q] [-C] [-h].. [--example] [-v] [FILES..]
Parse rust-peg traces, convert to tree

Options:
    -c, --center-rule   Rule name to centered
    -i, --ignore NAME   Ignore a rule
    -I, --ignore-partial NAME
                        Ignore a rule, support partial pattern
    -u, --unique-line   One rule one line
    -L, --last-width    Share width to last
        --share-width STYLE
                        Share width style (mixed, first, last)
    -e, --exclude-fails 
                        Exclude failed matches
    -r, --pair-fails    Add unpaired failed matches
    -w, --full-width-tab-chars 
                        Full-width tab chars
    -s, --fake-source   Using oneline fake source
    -S, --fake-source-from SRC
                        Using oneline fake source
    -q, --unquote-space 
                        Unquote space
    -C, --show-cached   Show cached match and fail
    -h, --help          Show help messages
        --example       Show example usage
    -v, --version       Show version

.set_usage_column(35):

Usage: pegview [-c] [-i NAME].. [-I NAME].. [-u] [-L] [--share-width STYLE] [-e] [-r] [-w] [-s] [-S SRC] [-q] [-C] [-h].. [--example] [-v] [FILES..]
Parse rust-peg traces, convert to tree

Options:
    -c, --center-rule              Rule name to centered
    -i, --ignore NAME              Ignore a rule
    -I, --ignore-partial NAME      Ignore a rule, support partial pattern
    -u, --unique-line              One rule one line
    -L, --last-width               Share width to last
        --share-width STYLE        Share width style (mixed, first, last)
    -e, --exclude-fails            Exclude failed matches
    -r, --pair-fails               Add unpaired failed matches
    -w, --full-width-tab-chars     Full-width tab chars
    -s, --fake-source              Using oneline fake source
    -S, --fake-source-from SRC     Using oneline fake source
    -q, --unquote-space            Unquote space
    -C, --show-cached              Show cached match and fail
    -h, --help                     Show help messages
        --example                  Show example usage
    -v, --version                  Show version