Ipset bootstrap

[TechnologyClassroom]

This patch to fortress.pl solves #5 and was a collaboration with @mplscorwin and myself.

I wrote a generic installer file that should work for most Debian and Red Hat based systems without the need to install from a package.

While I was tinkering with the package, I made some other changes that are listed below.

• I added an install category to the README.md file and wrapped lines at 80 characters.
• excludes/
  • I updated the Googlebot excludes list with the values that Google reports today and shared the commands that I used to generate the list within that file. I do have a script that can generate CIDR lists for ASNs, but I am starting with this one.
  • Added loopback CIDR to my.txt list.
• Licensing
  • I added standard license headers matching the LICENSE file in all .sh and .pl files throughout.
  • I added SPDX notation to the centos file.
  • I replaced the Adblock Plus (GPL-3.0-or-later) logo with a very similar CC0 image. The image is still a stop sign with a hand icon, but slightly different. The file size, image dimensions, and bitrate are all matching what was there before. I used GIMP.
• I removed the TODO.md file and filed issues for all of those feature requests. I made a few feature requests that I noticed as well.
• Ran shellcheck on the *.sh files and put more variables in double-quotes.
• Fixed some typos.
• Reduced long lines in bash scripts.
• I removed trailing spaces and tabs.

I did not use generative AI. These code commits were written on a terminal by a human.

Edit: Added shellcheck commit and description.

Edit: GitHub does not really give the user making a pull request a clean preview of what all is being included in a pull request before making one. Sorry! If you want me to clean these up and resubmit as smaller discrete patches I can. Doing all of that without hearing from you would just be a bunch of noise at this point though. We are planning on using this on some production servers that are seeing SYN floods. I really appreciate your project.

Edit 2: This does not work yet. We're fixing.

Edit 3: This patch now works, but now I am not sure that reading from /proc/net/tcp is a method that works for this anymore.

Edit 4: I closed my other pull request and copied the text to this one since they are also included in this one. I can still separated it out into small parts if you want.