Documentation for `magma_free` repeats the same description and example 2 times, and is incorrect/incomplete

[maxale]

The page https://doc.sagemath.org/html/en/reference/interfaces/sage/interfaces/magma_free.html

• says "Evaluate MAGMA code without requiring that MAGMA be installed on your computer by using the free online MAGMA calculator." and gives the same code example 2 times;
• incorrectly states time limitation as 20 seconds, while the actual limit is 120 seconds, according to http://magma.maths.usyd.edu.au/calc/
• does not explain parameters strip=True and columns=0.

[siddharthbaleja7]

@mkoeppe Can you assign this issue to me?

[Demon-Sheriff]

@mkoeppe if this issue still open, I would like to work on this one.

[maxale]

@Demon-Sheriff: you don't need a permission to fix this (or any other) issue. Please just create a pull request with a fix and give a link to it here.