vacuumdb: add page

[fabioperrella]

• 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.
• Version of the command being documented (if known):

[tldr-bot]

The build for this PR failed with the following error(s) at commit
8753ab9db4013078078f2d60fcbccf067a3ae120:

pages/common/vacuumdb.md:3: TLDR003 Descriptions should start with a capital letter

Please fix the error(s) and push again.