Clean up license (#832)Co-authored-by: pre-commit-ci[bot] <66853113+p…

…re-commit-ci[bot]@users.noreply.github.com>

* add license file

* replace COPYING.md with LICENSE (including references)

* move "About the IPython Development Team" section to README.md

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

LICENSE

@@ -0,0 +1,30 @@
+BSD 3-Clause License
+
+- Copyright (c) 2001-, IPython Development Team
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

README.md

@@ -188,3 +188,31 @@ with parity_check.hold_trait_notifications():
 
 However, we **recommend** that custom cross-validators don't modify the state
 of the HasTraits instance.
+
+## About the IPython Development Team
+
+The IPython Development Team is the set of all contributors to the IPython project.
+This includes all of the IPython subprojects.
+
+The core team that coordinates development on GitHub can be found here:
+https://github.com/jupyter/.
+
+## Our Copyright Policy
+
+IPython uses a shared copyright model. Each contributor maintains copyright
+over their contributions to IPython. But, it is important to note that these
+contributions are typically only changes to the repositories. Thus, the IPython
+source code, in its entirety is not the copyright of any single person or
+institution. Instead, it is the collective copyright of the entire IPython
+Development Team. If individual contributors want to maintain a record of what
+changes/contributions they have specific copyright on, they should indicate
+their copyright in the commit message of the change, when they commit the
+change to one of the IPython repositories.
+
+With this in mind, the following banner should be used in any source code file
+to indicate the copyright and license terms:
+
+```
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
+```

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "hatchling.build"
 name = "traitlets"
 authors = [{name = "IPython Development Team", email = "ipython-dev@python.org"}]
 description = "Traitlets Python configuration system"
-license = {file = "COPYING.md"}
+license = {file = "LICENSE"}
 readme = "README.md"
 keywords = ["Interactive", "Interpreter", "Shell", "Web"]
 classifiers = [