Implement a text mode for non-wordlist text files

[gwn]

Hello, this is a nice little typing tutor, thanks for this :)

Don't know if you'd be interested but I will be making a couple of
pull requests for the changes I made in my own fork. Cheers.

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Users can now supply any kind of plain text file to type its
contents exactly; as opposed to the shuffled word approach of the
wordlist mode.

One gotcha is that since the typing stage is of width 80, the
user-supplied text file should be word wrapped to 80 columns or it
will break the layout.

We can either add a warning to the docs regarding this issue; or
make the width configurable; or word-wrap the user-supplied text
file automatically to 80 columns.

[balzss]

Hi, thanks for the contribution! I will try to find some time to go over your code as soon as I can. I like the idea of a plain text mode.

Regarding the wrapping problem: I like the "configurable width" solution because it would be useful even for normal use. Or that could be combined with the automatic formatting so if the user defines a width then it formats the text to fit that width. What do you think about this?

[qwhex]

@gwn @balzss I think the "configurable width" feature should be done as a separate project, although this pull request is incomplete without automatic word-wrapping.

[gmcz]

I think it'd be great if the plain text mode could support shuffling paragraphs. For example:

Users can now supply any kind of plain text file to type its
contents exactly; as opposed to the shuffled word approach of the
wordlist mode.

One gotcha is that since the typing stage is of width 80, the
user-supplied text file should be word wrapped to 80 columns or it
will break the layout.

We can either add a warning to the docs regarding this issue; or
make the width configurable; or word-wrap the user-supplied text
file automatically to 80 columns.

Would randomly select one of the three paragraphs.