feat: Add support for bulleted lists in body

The body now supports bulleted lists. It follows the following rules:
 - Either an asterisk (*) or dash (-) can be used to denote the start of
   a bulleted line.
 - The bullet symbol must be the first non-whitespace character on a
   line.
 - All previous whitespace before the symbol is ignored. This means
   there is no support for nested lists.
 - For long lines, text will be automatically wrapped and indented to
   ensure that it is aligned with the text on the first and previous
   lines.
 - It will always ensure there is precisely one space before and after
   the bullet character, followed immediately by the text of the line.

Resolve #20

Author: nebbles

gitcommit/gitcommit.py

@@ -300,9 +300,21 @@ def add_body(commit_msg):
             if num_blank_lines > 1:
                 continue  # ignore any blank lines after the first
             else:
+                # check if we are dealing with a bulleted line
+                bulleted_line = False
+                if l_stripped[0] in ["*", "-"]:
+                    bulleted_line = True
+                    line_after_bullet = l_stripped[1:].strip()
+                    l_stripped = " " + l_stripped[0] + " " + line_after_bullet
+
                 # format each line with forced line breaks to maintain maximum line length
                 wrapped_line = "\n".join(
-                    textwrap.wrap(l_stripped, width=72, break_long_words=False)
+                    textwrap.wrap(
+                        l_stripped,
+                        width=72,
+                        break_long_words=False,
+                        subsequent_indent="   " if bulleted_line else "",
+                    )
                 )
                 condensed_b_lines.append(wrapped_line)