Avoid using whitespace to replace tab characters

[javier-godoy]

According to the rules as written:

In any file format, avoid using tab characters to replace a fixed amount of whitespace in any file format, as their display can differ across devices and platforms.

As discussed in #46 , formatting must be consistent.

The following case must be forbidden:

⟶line 1
⟶line 2
⟶line 3
··line 4

Proposal

Where it reads

avoid using tab characters to replace a fixed amount of whitespace

It must read:

avoid using tab characters to replace a fixed amount of whitespace (or vice versa)