Add popular open-source license templates

Add eight license templates:
- Apache2.txt: Apache License 2.0
- BSD2.txt: BSD 2-Clause License
- BSD3.txt: BSD 3-Clause License
- GPLv2.txt: GNU General Public License v2
- ISC.txt: ISC License
- LGPL.txt: GNU Lesser General Public License v3
- MIT0.txt: MIT No Attribution License (0-Clause MIT)
- MPL2.txt: Mozilla Public License v2.0
- Unlicense.txt: Unlicense (public domain)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

licenses/MIT0.txt

@@ -0,0 +1,18 @@
+MIT No Attribution License (MIT-0)
+
+Copyright (c) YEAR AUTHOR
+
+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.
+
+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.