feat: read words sequentially

[duot]

Hi there,

I want to practice over existing (non-randomized) texts. I'm toying with this. Maybe eventually, we can do something like cat sample.txt | toipe.

What do you think of this idea?

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This change will read words in a text file in sequence. No piping support yet. (Apologies in advance for bad Rust. I'm new to it).

The -s (sequential) flag must be provided in combination with -f.

Limitations:

• -n must be provided for long texts (over default 30)
• files with too many lines will not fit the screen
• there's no scrolling yet
• word/character filtering may need to be tweaked

[duot]

Oops. I didn't realize that a similar work, #57, is already underway 🤦