Add citation.cff and note for citing in README #57

Signed-off-by: Chin Yeung Li <[email protected]>

Author: chinyeungli

CITATION.cff

@@ -0,0 +1,19 @@
+cff-version: 1.2.0
+message: If you use this software, please cite it using these metadata.
+title: ScanCode-Toolkit
+authors:
+    - family-names: Philippe
+      given-names: Ombredanne
+      orcid: 'https://orcid.org/0000-0001-5280-9256'
+    - family-names: Ayan
+      given-names: Sinha Mahapatra
+    - family-names: Jono
+      given-names: Yang
+    - family-names: Georg
+      given-names: Brandl
+    - name: 'nexB Inc. and others.'
+license: Apache-2.0
+url: 'https://github.com/aboutcode-org/scancode-toolkit'
+# version: <ToDo>
+# date-released: <ToDo>
+# doi: <ToDo>

README.rst

@@ -134,6 +134,9 @@ Other Important Documentation Pages:
 
 See also https://aboutcode.org for related companion projects and tools.
 
+To cite this repository, visit the main page and click on the 'Cite this
+repository' button for APA or BibTeX citation formats.
+
 
 Installation
 ============