Heavily based on #1994.
Integrate Poetry virtualenv detection into the existing virtualenv
segment. For poetry virtualenvs, use the package name as reported by
`poetry version`.
- Link to the project's homepage rather than its source code.
- Move `chezmoi_shell` next to all the other *shell indicator* segments.
- Use a shade of blue that resembes the color on chezmoi.io.
- Don't go beyond 8 colors in 8-color configs.
- Remove the segment from the *pure* config.
- Fix whitespace padding on `CHEZMOI_ICON`.
- Use the appropriate icon with all fonts (the same as `HOME`).
- Add missing `CHEZMOI_ICON` definitions for "powerline" and "ascii" font modes.
- Remove the redundant literal "chezmoi" content from the segment.
- Fix instant prompt so that the segment is shown only when `$CHEZMOI` is non-empty.
- use POWERLEVEL9K_ICON_PADDING instead of
POWERLEVEL9K_VISUAL_IDENTIFIER_EXPANSION to customize padding after
icons
- remove reliance on UTF-8 locale when the config is being sourced
- non-permanent content location (left or right)
- show current time
- prompt height (one or two lines)
- prompt spacing (with empty line between prompts or without)
