Updates from the package template (#308)

* Automatic package template update

* Update README.rst

---------

Co-authored-by: Cadair <1391051+Cadair@users.noreply.github.com>
Co-authored-by: Stuart Mumford <stuart@cadair.com>

Author: github-actions[bot]

.cruft.json

@@ -1,6 +1,6 @@
 {
   "template": "https://github.com/sunpy/package-template",
-  "commit": "9599f755e4f7880fe20f0f07bbf500d8c41de34d",
+  "commit": "6436220cebd96b3638682023e7149eb78e012fdc",
   "checkout": null,
   "context": {
     "cookiecutter": {
@@ -33,7 +33,7 @@
         ".github/workflows/sub_package_update.yml"
       ],
       "_template": "https://github.com/sunpy/package-template",
-      "_commit": "9599f755e4f7880fe20f0f07bbf500d8c41de34d"
+      "_commit": "6436220cebd96b3638682023e7149eb78e012fdc"
     }
   },
   "directory": null

README.rst

@@ -1,6 +1,8 @@
 ``sunkit-image``
 ================
 
+An image processing toolbox for Solar Physics.
+
 |Latest Version| |codecov| |Powered by NumFOCUS| |Powered by Sunpy|
 
 .. |Powered by Sunpy| image:: http://img.shields.io/badge/powered%20by-SunPy-orange.svg?style=flat
@@ -12,8 +14,7 @@
 .. |Powered by NumFOCUS| image:: https://img.shields.io/badge/powered%20by-NumFOCUS-orange.svg?style=flat&colorA=E1523D&colorB=007D8A
    :target: http://numfocus.org
 
-``sunkit-image`` is a a open-source toolbox for solar physics image processing.
-Currently it is an experimental library for solar physics specific image processing routines.
+Currently this is an experimental library for solar physics specific image processing routines.
 Ideally it will only contain routines that have been published in the literature.
 
 See `sunkit-image Documentation <https://docs.sunpy.org/projects/sunkit-image/en/stable/>`__ for instructions on how to install and contribute.