docs: update related packages sections

[stdlib-bot]

This PR

• updates the related packages section of READMEs to include links to related packages.

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
random/array/lognormal	$\color{green}212/212$ $\color{green}+100.00%$	$\color{green}3/3$ $\color{green}+100.00%$	$\color{green}0/0$ $\color{green}+100.00%$	$\color{green}212/212$ $\color{green}+100.00%$
random/base/chisquare	$\color{green}375/375$ $\color{green}+100.00%$	$\color{green}44/44$ $\color{green}+100.00%$	$\color{green}10/10$ $\color{green}+100.00%$	$\color{green}375/375$ $\color{green}+100.00%$
random/base/invgamma	$\color{green}462/462$ $\color{green}+100.00%$	$\color{green}53/53$ $\color{green}+100.00%$	$\color{green}11/11$ $\color{green}+100.00%$	$\color{green}462/462$ $\color{green}+100.00%$
random/base/normal	$\color{green}489/489$ $\color{green}+100.00%$	$\color{green}55/55$ $\color{green}+100.00%$	$\color{green}12/12$ $\color{green}+100.00%$	$\color{green}489/489$ $\color{green}+100.00%$
random/chisquare	$\color{green}215/215$ $\color{green}+100.00%$	$\color{green}3/3$ $\color{green}+100.00%$	$\color{green}0/0$ $\color{green}+100.00%$	$\color{green}215/215$ $\color{green}+100.00%$

The above coverage report was generated for the changes in this PR.