Add info about the CPython core sprint

src/content/sprints/cpython.md

@@ -0,0 +1,33 @@
+---
+title: "CPython Core"
+numberOfPeople: "TBA"
+pythonLevel: "Intermediate"
+contactPerson:
+  name: "Petr Viktorin"
+  email: encukou@gmail.com
+  github: encukou
+links:
+  - title: "CPython's Developer Guide"
+    url: "https://devguide.python.org/"
+  - title: "Setup & Building"
+    url: "https://devguide.python.org/getting-started/setup-building/"
+  - title: "Code of Conduct"
+    url: "https://policies.python.org/python.org/code-of-conduct/"
+  - title: "Easy Issues"
+    url: "https://github.com/python/cpython/issues?q=is%3Aissue+is%3Aopen+label%3Aeasy"
+---
+
+Come sprint on CPython and work on Python 3.15 and 3.16!
+
+Sprints will focus on release candidate fixes to Python 3.15 (to be released
+this October), with some limited new feature work for 3.16 (final version in
+October 2027).
+
+1. Recommended for Python users with 2+ years of experience.
+2. Read
+   [what to expect](https://pycon.blogspot.com/2025/04/pyconus-sprints.html)
+   (about PyCon US sprints, but a lot applies here!).
+3. Fork and clone the repository _before_ coming to the venue in case of slow
+   wifi :)
+4. Use the [Python Developer's Guide](https://devguide.python.org/) to go
+   through the initial build on you machine.