removes unnecssary --save flag (added by default in npm > 5).
Adds an example that installs a package wihtout a version since thats a simpler case.
Moves the global install example down the page since it's a more complicated case
Switch to the longversion of global option (`--global`) instead of `-g` to comply with styleguide
Simplified description of adding dependency
Switched from the terms "dependency" and "module" to "package" where possible since package is more idiomatic in this context.
Remove `npm list --global` example to keep page under 8 example limit
5f5cd8759e