Hints on cryptography about "random" modules

[lucasloisp]

Closes #774 by creating a HINTS.md file for every exercise involving cryptography or the use of random module.

The wording is as follows

Hints

Should I use random or secrets?

Python, as of version 3.6, includes two different random modules.

The module called random is pseudo-random, meaning it does not generate
true randomness, but follows an algorithm that simulates randomness.
Since random numbers are generated through a known algorithm, they are not truly random.

The random module is not correctly suited for cryptography and should not be used,
precisely because it is pseudo-random.

For this reason, in version 3.6, Python introduced the secrets module, which generates
cryptographically strong random numbers that provide the greater security required for cryptography.

Since this is only an exercise, random is fine to use, but note that it would be
very insecure if actually used for cryptography.

[N-Parsons]

@lucasloisp, I believe that the hints file should be located at .meta/hints.md in order for the configlet to find it and incorporate it into the README - you can find details for this in the configlet's README.

Some of these exercises don't seem to require randomness, specifically:

• atbash-cipher
• crypto-square
• rail-fence-cipher
• rotational-cipher

I also wouldn't consider robot-name to be a cryptographic exercise - there are times where random is the most suitable module.

[lucasloisp]

Noted! I've made the necessary updates

[ilya-khadykin]

Thanks for the PR

Please read my comment

[ilya-khadykin]

Could you please rename the file to hints.md (lowercase) for consistency

[lucasloisp]

Done! I'd done it but apparently there was some error in renaming

[ilya-khadykin]

Looks good to me

@N-Parsons could you take a look?

[N-Parsons]

Heading level 1 here is going to be a the wrong level for the README - the first level in this document should be level 2 (##). Personally, I would just delete this heading and keep the one below - two headings for one thing would seem strange in the flow of the README.

[N-Parsons]

This README (and the one for simple-cipher) will need either regenerating to include the hint. Alternatively, you can just copy-and-paste it in at this location.

[lucasloisp]

Ready

[N-Parsons]

@lucasloisp, the section needs to go before ### Submitting Exercises, since that's where it goes if we regenerate the file.

[N-Parsons]

As above, I think like line should just be removed.