doc: Rename sphinx-gallery's README.txt to GALLERY_HEADER.rst and require Sphinx-Gallery>=0.17.0 (#3348)

Author: seisman

doc/_templates/breadcrumbs.html

@@ -14,7 +14,7 @@
                 {% set gallery_path = gallery_dir[pagename.split("/")[0]] %}
                 {% set example_script = pagename|replace(pagename.split("/")[0], gallery_dir[pagename.split("/")[0]]) %}
                 {% if pagename.split("/")[-1] == "index" %}
-                    {% set example_script = example_script|replace("index", "README.txt") %}
+                    {% set example_script = example_script|replace("index", "GALLERY_HEADER.rst") %}
                 {% else %}
                     {% set example_script = example_script + ".py" %}
                 {% endif %}

environment.yml

@@ -40,7 +40,7 @@ dependencies:
     - sphinx-autodoc-typehints
     - sphinx-copybutton
     - sphinx-design
-    - sphinx-gallery
+    - sphinx-gallery>=0.17.0
     - sphinx_rtd_theme
     # Dev dependencies (type hints)
     - mypy