Export types & doc improvements (#2329)

* Export types used in app.py

* Export more linked types/errors/classes.

* Remove custom template.

* Address review comments.

We need to have explicit 'Returns:' sections in properties if we want to link to the return type while https://github.com/mkdocstrings/python/issues/65 is open.

* Improve docs.

docs/_templates/python/material/attribute.html

@@ -1,67 +0,0 @@
-{{ log.debug("Rendering " + attribute.path) }}
-
-<div class="doc doc-object doc-attribute">
-{% with html_id = attribute.path %}
-
-  {% if root %}
-    {% set show_full_path = config.show_root_full_path %}
-    {% set root_members = True %}
-  {% elif root_members %}
-    {% set show_full_path = config.show_root_members_full_path or config.show_object_full_path %}
-    {% set root_members = False %}
-  {% else %}
-    {% set show_full_path = config.show_object_full_path %}
-  {% endif %}
-
-  {% if not root or config.show_root_heading %}
-
-    {% filter heading(heading_level,
-        role="data" if attribute.parent.kind.value == "module" else "attr",
-        id=html_id,
-        class="doc doc-heading",
-        toc_label=attribute.name) %}
-
-      {% if config.separate_signature %}
-        <span class="doc doc-object-name doc-attribute-name">{% if show_full_path %}{{ attribute.path }}{% else %}{{ attribute.name }}{% endif %}</span>
-      {% else %}
-        {% filter highlight(language="python", inline=True) %}
-          {% if show_full_path %}{{ attribute.path }}{% else %}{{ attribute.name }}{% endif %}
-          {% if attribute.annotation %}: {{ attribute.annotation }}{% endif %}
-        {% endfilter %}
-      {% endif %}
-
-      {% with labels = attribute.labels %}
-        {% include "labels.html" with context %}
-      {% endwith %}
-
-    {% endfilter %}
-
-    {% if config.separate_signature %}
-      {% filter highlight(language="python", inline=False) %}
-        {% filter format_code(config.line_length) %}
-          {% if show_full_path %}{{ attribute.path }}{% else %}{{ attribute.name }}{% endif %}
-          {% if attribute.annotation %}: {{ attribute.annotation|safe }}{% endif %}
-        {% endfilter %}
-      {% endfilter %}
-    {% endif %}
-
-  {% else %}
-    {% if config.show_root_toc_entry %}
-      {% filter heading(heading_level,
-          role="data" if attribute.parent.kind.value == "module" else "attr",
-          id=html_id,
-          toc_label=attribute.path if config.show_root_full_path else attribute.name,
-          hidden=True) %}
-      {% endfilter %}
-    {% endif %}
-    {% set heading_level = heading_level - 1 %}
-  {% endif %}
-
-  <div class="doc doc-contents {% if root %}first{% endif %}">
-    {% with docstring_sections = attribute.docstring.parsed %}
-      {% include "docstring.html" with context %}
-    {% endwith %}
-  </div>
-
-{% endwith %}
-</div>

docs/api/errors.md

@@ -0,0 +1 @@
+::: textual.errors

docs/api/filter.md

@@ -0,0 +1 @@
+::: textual.filter

docs/api/scrollbar.md

@@ -0,0 +1 @@
+::: textual.scrollbar

docs/api/types.md

@@ -0,0 +1 @@
+::: textual.types