Add CITATION.cff file for easier repo citation (#498)

* Add CITATION.cff file for easier repo citation

GitHub has added native support of the CITATION.cff file format, which
provides a nice way to generate a citation for a software repository.

This adds in a basic citation.cff file, which can be updated as
necessary.

* Include foyer reference and clean up names

* Update preferred citation and message.

* update format

* fix schema issue

Co-authored-by: Co Quach <daico007@gmail.com>

CITATION.cff

@@ -0,0 +1,118 @@
+# This CITATION.cff file was generated with cffinit.
+# Visit https://bit.ly/cffinit to generate yours today!
+
+cff-version: 1.2.0
+title: >-
+  Foyer: A package for atom-typing as well as
+  applying and disseminating forcefields
+message: >-
+  If you use this software, please cite it using the
+  metadata from this file and the preferred citation.
+type: software
+authors:
+  - given-names: Christoph
+    family-names: Klein
+    affiliation: "Vanderbilt University"
+  - given-names: "Andrew Z."
+    family-names: Summers
+    affiliation: "Vanderbilt University"
+    orcid: 'https://orcid.org/0000-0001-8477-3059'
+  - given-names: "Matthew W."
+    family-names: Thompson
+    affiliation: "Vanderbilt University"
+    orcid: 'https://orcid.org/0000-0002-1460-3983'
+  - given-names: "Justin B."
+    family-names: Gilmer
+    affiliation: "Vanderbilt University"
+    orcid: 'https://orcid.org/0000-0002-6915-5591'
+  - given-names: "Co D."
+    family-names: Quach
+    affiliation: "Vanderbilt University"
+    orcid: 'https://orcid.org/0000-0002-1255-4161'
+  - given-names: Umesh
+    family-names: Timalsina
+    affiliation: "Vanderbilt University"
+    orcid: 'https://orcid.org/0000-0002-5430-3993'
+  - given-names: Peter
+    family-names: Volgyesi
+    orcid: 'https://orcid.org/0000-0002-7478-4317'
+    affiliation: "Vanderbilt University"
+  - given-names: Janos
+    family-names: Sallai
+    affiliation: "Vanderbilt University"
+  - given-names: "Chris R."
+    family-names: Iacovella
+    affiliation: "Vanderbilt University"
+    orcid: 'https://orcid.org/0000-0003-0557-0427'
+  - given-names: Clare
+    family-names: McCabe
+    affiliation: "Vanderbilt University"
+    orcid: 'https://orcid.org/0000-0002-8552-9135'
+  - given-names: "Peter T."
+    family-names: Cummings
+    affiliation: "Vanderbilt University"
+    orcid: 'https://orcid.org/0000-0002-9766-2216'
+identifiers:
+  - type: doi
+    value: 10.5281/zenodo.6229092
+    description: Zenodo Doi
+repository-code: 'https://github.com/mosdef-hub/foyer'
+url: 'https://foyer.mosdef.org'
+repository: 'https://github.com/mosdef-hub/foyer'
+repository-artifact: 'https://github.com/mosdef-hub/foyer/releases'
+abstract: >-
+  Foyer is an open-source Python tool for defining
+  and applying force field atom-typing rules in a
+  format that is both human- and machine-readable. It
+  parametrizes chemical topologies, generating,
+  syntactically correct input files for various
+  simulation engines. Foyer provides a framework for
+  force field dissemination, helping to eliminate
+  ambiguity in atom-typing and improving
+  reproducibility.
+keywords:
+  - atom-typing
+  - reproducibility
+  - 'TRUE'
+  - mosdef
+  - python
+license: MIT
+preferred-citation:
+  type: article
+  authors:
+    - given-names: Christoph
+      family-names: Klein
+      affiliation: "Vanderbilt University"
+    - given-names: "Andrew Z."
+      family-names: Summers
+      affiliation: "Vanderbilt University"
+      orcid: 'https://orcid.org/0000-0001-8477-3059'
+    - given-names: "Matthew W."
+      family-names: Thompson
+      affiliation: "Vanderbilt University"
+      orcid: 'https://orcid.org/0000-0002-1460-3983'
+    - given-names: "Justin B."
+      family-names: Gilmer
+      affiliation: "Vanderbilt University"
+      orcid: 'https://orcid.org/0000-0002-6915-5591'
+    - given-names: Clare
+      family-names: McCabe
+      affiliation: "Vanderbilt University"
+      orcid: 'https://orcid.org/0000-0002-8552-9135'
+    - given-names: "Peter T."
+      family-names: Cummings
+      affiliation: "Vanderbilt University"
+      orcid: 'https://orcid.org/0000-0002-9766-2216'
+    - given-names: Janos
+      family-names: Sallai
+      affiliation: "Vanderbilt University"
+    - given-names: "Chris R."
+      family-names: Iacovella
+      affiliation: "Vanderbilt University"
+      orcid: 'https://orcid.org/0000-0003-0557-0427'
+  title: "Formalizing atom-typing and the dissemination of force fields with foyer"
+  journal: "Comput. Mater. Sci."
+  volume: "167"
+  pages: "12"
+  year: "2019"
+  doi: "10.1016/j.commatsci.2019.05.026"