build(github): make cafkafk codeowner of everything

This makes me the codeowner of all files, meaning any PR will request me
for review. While this should (hopefully) be changed later to offload
the review burden, it's nice in the start of a project to ensure things
get prompt reviews.

Ideally, we'll have codeowners for specific sections of the code, e.g.
critical parts, as well as parts where people have domain specific
knowledge.

Signed-off-by: Christina Sørensen <christina@cafkafk.com>

.github/CODEOWNERS

@@ -0,0 +1,31 @@
+# SPDX-FileCopyrightText: 2023 Christina Sørensen
+# SPDX-FileContributor: Christina Sørensen
+#
+# SPDX-License-Identifier: AGPL-3.0-only
+
+# Lines starting with a '#' are comments.
+# Each line is a file pattern followed by one or more owners.
+
+# These owners will be the default owners for everything in the repository.
+# * @global-owner1 @global-owner2
+
+# The 'docs/*' pattern will match files like
+# 'docs/getting-started.md' but not further nested files like
+# 'docs/build-app/troubleshooting.md'.
+# docs/*  @doc-owner-team
+
+# You can also use email addresses if the user isn't on GitHub.
+# *.py admin@example.com
+
+# You can use a '*' at the end of a pattern to match all files
+# of a particular type.
+# *.* @all-file-types-owner
+
+# Order is important. The last matching pattern has the most precedence.
+# This means if a pull request touches both *.js and *.css files,
+# it will only request a review from @js-owner, not @css-owner.
+# *.js @js-owner
+# *.css @css-owner
+
+# Automatically request my review on all changes
+* @cafkafk