Review /docs contents

[neverbot]

The contents of the /docs directory are outdated, mostly copied from old muds, using the concepts of efun/lfun from mudos. They have to be cleaned.

• [ ] Check duplicities with languages, now we have /docs/en and /docs/es and maybe the languages are not correct. Look for original english doc if we only have a translated one.
• [ ] Removed outdated files from older muds.
• [ ] Mix lfun/efun contents if needed.
• [x] Update installation instructions.
• [ ] Review help cmd.
• [ ] Review man cmd.

[neverbot]

Not urgent, moved to next milestone (2.1) after reaching beta.