pacman-*,npm-*,magick-mogrify,shnsplit: update and add Dutch translation

[sebastiaanspeck]

• The page(s) are in the correct platform directories: common, linux, osx, windows, sunos, android, etc.
• The page(s) have at most 8 examples.
• The page description(s) have links to documentation or a homepage.
• The page(s) follow the content guidelines.
• The page(s) follow the style guide.
• The PR title conforms to the recommended templates.

[tldr-bot]

Hello! I've noticed something unusual when checking this PR:

• The page pages.nl/common/npm-list.md seems to be a copy of pages.nl/windows/sdelete64.md (73% matching).

Is this intended? If so, just ignore this comment. Otherwise, please double-check the commits.