[pygobject] Add a readthedocs config

[Christoph Reiter <creiter src gnome org>]

commit 4355e36208237c0073d168bd0e6dee5b8c69cc30
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Sun Mar 27 18:55:25 2022 +0200

    Add a readthedocs config
    
    So it uses a newer sphinx

 .readthedocs.yaml     | 9 +++++++++
 MANIFEST.in           | 3 ++-
 docs/requirements.txt | 2 ++
 3 files changed, 13 insertions(+), 1 deletion(-)
---
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
new file mode 100644
index 00000000..a862d409
--- /dev/null
+++ b/.readthedocs.yaml
@@ -0,0 +1,9 @@
+version: 2
+
+sphinx:
+  configuration: docs/conf.py
+
+python:
+  version: '3.8'
+  install:
+    - requirements: docs/requirements.txt
\ No newline at end of file
diff --git a/MANIFEST.in b/MANIFEST.in
index fad3bfd6..9fa260d6 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -7,12 +7,13 @@ include tools/pygi-convert.sh
 include pygobject.doap
 include README.rst
 include .gitlab-ci.yml
+include *.yaml
 include subprojects/*.wrap
 include meson.build
 include meson_options.txt
 recursive-include examples *.py *.png *.css *.ui *.gif *.gresource *.jpg *.xml
 recursive-include gi *.h meson.build
 recursive-include tests *.py *.c *.h *.xml *.supp meson.build
-recursive-include docs *.rst *.svg LICENSE *.ico *.png *.css *.py *.dia Makefile
+recursive-include docs *.rst *.svg LICENSE *.ico *.png *.css *.py *.dia Makefile *.txt
 recursive-include .gitlab-ci *.sh *.rst *.py Dockerfile* lcovrc
 recursive-include pygtkcompat meson.build
diff --git a/docs/requirements.txt b/docs/requirements.txt
new file mode 100644
index 00000000..6564150d
--- /dev/null
+++ b/docs/requirements.txt
@@ -0,0 +1,2 @@
+sphinx>=4.0,<5.0
+sphinx-rtd-theme>=0.5,<2.0
\ No newline at end of file