learn(fs): refresh

[AugustinMauroy]

IMO, the part about the FS is not quite right and there are missing parts.

• The title of subsection "Manipulating Files" should be something like "working with file system" because the content is just not about file it's also about folder.
• Adding a intorudction of fs/fs/promises + what mean file system ... like introduction of test runner
• Include glob paterns
• more examples with cjs/esm

Remaining question:

• Should we put ESM example as first ?
• Should we put fs/promises as first.
• How to handle difference between fs and fs/promises

[AugustinMauroy]

cc @nodejs/fs What is your opinion on that ?