Added extra answers

[altmind]

I've added multiple missing answers.

I tried to break it down to multiple PRs, but there are too many changes. I've added couple of answers to the best of my knowledge.

I had to remove two questions as they were either too opinionated, or did not make technical sense:

• Why do most distros use ext4, as opposed to XFS or other filesystems? Why are there so many of them? (factually untrue, opinionated)
• What does CPU jumps mean? (the screenshot linked asks about context switches, and the numbers are normal. the linked stackoverflow answer is mumbo-jumbo. non-factual question+nonsensical answer removed)
• Tell me about the dangers and caveats of LVM. (rewritten the answer to emphasise that LVM have been 10 years enterprise ready and the benefits outweight the risks)
• How to change the kernel parameters? What kernel options might you need to tune? (The answer was talking about sysctl, not kernel parameters. I've added extended explanation about the kernel params)
• ls -l shows file attributes as question marks. What this means and what steps will you take to remove unused "zombie" files (removed wrong root cause, and removed the resulting irrelevant steps)

[trimstray]

Hi! Your PR is amazing :) I will study the changes and give you an answer. Thanks a lot!