Log Message:
lowdown: update to 0.7.9 and take MAINTAINER.

ChangeLog:

Version 0.7.9, 2021-01-11

- Fix a crash introduced with the new UTF-8 handling in -Tterm.
- Allow the "section" metadata key to set the manpage section when used
  with -Tman.
- Significantly clean up lists (definition, ordered, unordered) and how
  indenting and compacting is handled in -Tman and -Tms.
- Use EX and EE for block code when in -Tman. These only apply in
  LOWDOWN_NROFF_GROFF mode. While looking at block codes, fix how much
  trailing space is emitted and make sure that subsequent paragraphs
  are indented.
- Don't have sections in -Tman be followed by superfluous paragraph
  macros (PP, etc.).

Version 0.7.7, 2021-01-06

Have the -Tterm output correctly adjust columns for UTF-8 wide characters.
This makes both ASCII and UTF-8 (e.g, Russian) correctly align on terminal
output.