Updates from the package template (sunpy#225)

* 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

@@ -1,7 +1,7 @@
-streamtracer
-============
+``streamtracer``
+================
 
-Fast streamline tracing in python
+Python library to calculate streamlines
 
 |Documentation Status| |Build Status| |codecov|