Replace most occurances of http with https when the https url is valid

[LilithHafner]

I searched the repo for "http:...", checked if equivalent "https:..." urls returned 200 status codes without authentication errors, and replace all occurances that did. Then I performed a manual review and reverted cases that should remain "http:".

Here's the script that performed the original replacement

using Random, HTTP
# disallow ) in url because it is so common to have [x](example.com)
links = readlines(`ag -o --nofilename --nogroup --hidden "http:[A-Za-z0-9-._~:/?#\[\]@-l&'(*+,;%=]+"`)
filter!(!isempty, links)
unique!(links)

replacements = []
for link in shuffle!(links)
    link_secure = link[1:4] * "s" * link[5:end]

    status = try
        HTTP.get(link_secure, retry=false, connect_timeout=5, read_timeout=10).status
    catch e
        nothing
    end
    if status === Int16(200)
        push!(replacements, link => link_secure)
        println("okay: ", link_secure)
    else
        println("fail: ", link_secure)
    end
end


###
files = reduce(vcat, (readlines(`ag -Q --hidden -l $(r[1])`) for r in replacements))
unique!(sort!(files))
for file in files
    content = read(file, String)
    for r in replacements
        content = replace(content, r)
    end
    open(file, "w") do io
        write(io, content)
    end
end

This should be minor and mostly NFC.