Add "Citing" section to README and Book landing page

Author: jcfr

README.md

@@ -2,8 +2,26 @@
 
 [![Documentation Status](https://readthedocs.org/projects/vtk-book/badge/?version=latest)](https://book.vtk.org/en/latest/?badge=latest)
 
+## Citing
+
+When citing VTK in your scientific research, please mention the following work to support increased visibility and dissemination of our software:
+
+> Schroeder, Will; Martin, Ken; Lorensen, Bill (2006), The Visualization Toolkit (4th ed.), Kitware, ISBN 978-1-930934-19-1
+
+For your convenience here is a bibtex entry:
+
+```bibtex
+@Book{vtkBook,
+  author    = "Will Schroeder and Ken Martin and Bill Lorensen",
+  title     = "The Visualization Toolkit (4th ed.)",
+  publisher = "Kitware",
+  year      = "2006",
+  isbn      = "978-1-930934-19-1",
+}
+```
 
 ## Build environment
+
 To compile the document locally create a python virtual environment and install the required packages.
 For example in Linux / MacOS:
 ```

conf.py

@@ -23,10 +23,10 @@
 ]
 
 myst_enable_extensions = [ 
-  "linkify", # convert bare links to hyperlinks
-  "dollarmath", # support latex equation inside $ $
-  "amsmath",
-
+    "amsmath",
+    "dollarmath", # support latex equation inside $ $
+    "linkify", # convert bare links to hyperlinks
+    "sphinxcontrib.bibtex",
 ]
 myst_heading_anchors = 7
 

index.md

@@ -11,3 +11,20 @@ resources for the fourth edition of the  [VTK textbook](https://vtk.org/vtk-text
 about_page
 VTKBook/*
 ```
+## Citing
+
+When citing VTK in your scientific research, please mention the following work to support increased visibility and dissemination of our software:
+
+> Schroeder, Will; Martin, Ken; Lorensen, Bill (2006), The Visualization Toolkit (4th ed.), Kitware, ISBN 978-1-930934-19-1
+
+For your convenience here is a bibtex entry:
+
+```bibtex
+@Book{vtkBook,
+  author    = "Will Schroeder and Ken Martin and Bill Lorensen",
+  title     = "The Visualization Toolkit (4th ed.)",
+  publisher = "Kitware",
+  year      = "2006",
+  isbn      = "978-1-930934-19-1",
+}
+```

requirements.txt

@@ -1,4 +1,5 @@
-sphinx-book-theme
 myst-parser[linkify]
 pygments
 sphinx
+sphinx-book-theme
+sphinxcontrib-bibtex