Keyword search in flat description, new --no-cache and --max-monthly-fee arguments

[saattrupdan]

Added

• Added new --min-monthly-fee and --max-monthly-fee options to filter flats by
  monthly fee. The default is no minimum or maximum monthly fee.
• Added new --cache/--no-cache flag, which allows you to disable the cache. The
  default behaviour is still to use the cache, but you can disable it by using the
  --no-cache flag. This is useful if you want to see all the results, and not just the
  new ones. The cache is stored in the .boligping_cache file in the current directory.

Changed

• Changed the --query (-q) option to now search for the selected keywords in the
  description of the flat, rather than use Boligsiden.dk's own keywords, since many
  flats do not use these keywords. Remember that you can specify multiple queries with,
  e.g., bolig-ping <other-arguments> -q badekar -q altan.

[Copilot]

Pull Request Overview

This PR implements a feature to filter flat listings based on keywords supplied by the user through the CLI.

• Removed the use of Boligsiden.dk’s own keywords in URL generation by eliminating the "text" parameter.
• Updated the scraper to filter flats based on their description and modified the output from HTML to a text format.
• Adjusted tests, documentation, and the changelog to reflect these changes.

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/test_data_models.py	Updated expected URL output to remove the unused "text" parameter.
src/bolig_ping/scraper.py	Added filtering logic for keyword queries in flat descriptions.
src/bolig_ping/data_models.py	Introduced a new description property and a to_text method; removed URL query parameter based on queries.
src/bolig_ping/cli.py	Updated CLI option and output format to align with text-based results.
README.md	Updated coverage badge information.
CHANGELOG.md	Documented changes for the new keyword search feature.