reduce templates again to avoid clutter in published posts

.github/DISCUSSION_TEMPLATE/announcements.yml

@@ -1,7 +0,0 @@
-body:
-  - type: textarea
-    id: content
-    attributes:
-      label: Your announcement
-    validations:
-      required: true

.github/DISCUSSION_TEMPLATE/general.yml

@@ -1,9 +0,0 @@
-body:
-  - type: textarea
-    id: content
-    attributes:
-      label: Content
-      description: |
-        Please, put source code in [fenced code blocks with syntax highlighting](https://docs.github.com/en/get-started/writing-on-github/working-with-advanced-formatting/creating-and-highlighting-code-blocks#syntax-highlighting).
-    validations:
-      required: true

.github/DISCUSSION_TEMPLATE/ideas.yml

@@ -2,7 +2,7 @@ body:
   - type: textarea
     id: content
     attributes:
-      label: Describe your idea
+      label: Idea
       description: |
         If possible, give a [minimal reproducible code example](https://en.wikipedia.org/wiki/Minimal_reproducible_example).
         Put source code in [fenced code blocks with syntax highlighting](https://docs.github.com/en/get-started/writing-on-github/working-with-advanced-formatting/creating-and-highlighting-code-blocks#syntax-highlighting).

.github/DISCUSSION_TEMPLATE/q-a.yml

@@ -2,7 +2,7 @@ body:
   - type: textarea
     id: content
     attributes:
-      label: Describe your question
+      label: Question
       description: |
         Search through [existing questions](https://github.com/zauberzeug/nicegui/discussions/categories/q-a) first.
         If possible, give a [minimal reproducible code example](https://en.wikipedia.org/wiki/Minimal_reproducible_example).

.github/DISCUSSION_TEMPLATE/show-and-tell.yml

@@ -1,9 +0,0 @@
-body:
-  - type: textarea
-    id: content
-    attributes:
-      label: Describe your project
-      description: |
-        Please, put source code in [fenced code blocks with syntax highlighting](https://docs.github.com/en/get-started/writing-on-github/working-with-advanced-formatting/creating-and-highlighting-code-blocks#syntax-highlighting).
-    validations:
-      required: true

.github/ISSUE_TEMPLATE/issue.yml

@@ -4,7 +4,7 @@ body:
   - type: textarea
     id: content
     attributes:
-      label: Describe the issue
+      label: Description
       description: |
         1. What are you trying to do?
           If possible, give a [minimal reproducible code example](https://en.wikipedia.org/wiki/Minimal_reproducible_example).