Change Λrrow occurrences for Arrow

[calvellido]

This PR modifies all occurrences of referring to the library name as Λrrow for its proper name: Arrow.

While the usage of the uppercase lambda is cool, and it creates a nice effect on the text, it totally defeats the purpose of having accessible web content. And it also brings some inconsistencies and problems when writing the library name on different media, etc. It also creates the issue of the library name not being properly indexed by web crawlers and bots.

While some possible bypass for those problems could be the use of the aria-label property, it would really be a hacky shortcut misusing it, as that wouldn't be the goal of that HTML property. And all this while not really solving the underlying issue of having an improper (in terms of pure text) library name.

The usage of the uppercased lambda name, Λrrow, should only be used on display media like images, videos, and such, but never text content.

This closes #145

[raulraja]

Thanks @calvellido !

[nomisRev]

Awesome @calvellido!