add license, adjust readme

LICENSE.txt

@@ -0,0 +1,7 @@
+Copyright © 2021 Maximilian Keßler
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -1,6 +1,20 @@
-# LatexPackages
+# Latex Packages
 
-packages with mkessler- name are up to date
-package sheet is also usable
+This is a collection of some packages I regularly use. Feel free to use them as well, if you want to.
 
-other packages are deprecated
+However, some of them (especially `mkessler-math`) might be heavily customized for myself and do not form a real package in the Unix philosophy sense and are more of my preamble, that everyone gets to copy around that I bundled up in a central place. Some others (especially `mkessler-fancythm`) follow (or at least try to) this philosophy, so they should be designed to work with your documents and online provide specific functionality.
+
+Mostly, they are available as a repository so that
+- People that I work on the same documents with have access to all the source code I used, without having to send them package files each time
+- I can use these as a submodule in various other projects, e.g. the write-up of my lecture notes. This bundles re-usability and easy modifiability at a central place whilst also allowing project-specific (small) adaptations
+- I like sharing things that could help others, as I profit from others way too often
+- This motivates me to keep things organized
+
+## Bugs
+As already mentioned, not all of these are intended for generic use. If you however feel like this should be the case, feel free to point out bugs or troubles when using these here at GitHub or to me directly.
+
+## Contribute
+Feel free to send pull requests if you have suggestions for improvements.
+
+## License
+This is [MIT](https://mit-license.org/)-licensed and thus free software. You can freely share, distribute, modify and use these packages.