REUSE.toml: add annotation for files that may not contain licensing info

Add REUSE.toml to describe what license and copyright info applies to
files that may not contain licensing info in their headers.

Signed-off-by: Benjamin Cabé <[email protected]>

Author: kartben

REUSE.toml

@@ -0,0 +1,25 @@
+version = 1
+
+# Declare default license and copyright text for files that typically do not include them.
+[[annotations]]
+path = [
+    # zephyr-keep-sorted-start
+    "**/*.cfg",
+    "**/*.cmake",
+    "**/*.conf",
+    "**/*.ecl",
+    "**/*.html",
+    "**/*.rst",
+    "**/*.yaml",
+    "**/*.yml",
+    "**/*_defconfig",
+    "**/CMakeLists.txt",
+    "**/Kconfig*",
+    "doc/requirements.in",
+    "doc/requirements.txt",
+    "scripts/requirements-*.in",
+    "scripts/requirements-*.txt",
+    # zephyr-keep-sorted-stop
+]
+SPDX-License-Identifier = "Apache-2.0"
+SPDX-FileCopyrightText = "Copyright The Zephyr Project Contributors"