cp, mv, rm, rmdir, mkdir: add Czech translation

[Sarijen]

• 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):

pages.cs/common/cp.md:14: TLDR005 Example descriptions should end in a colon with no trailing characters
pages.cs/common/cp.md:18: TLDR005 Example descriptions should end in a colon with no trailing characters
pages.cs/common/cp.md:26: TLDR005 Example descriptions should end in a colon with no trailing characters
pages.cs/common/mv.md:22: TLDR005 Example descriptions should end in a colon with no trailing characters
pages.cs/common/rm.md:27: TLDR005 Example descriptions should end in a colon with no trailing characters

Please fix the error(s) and push again.