Attention Translators! Add "group" field to tiddler types

Apologies to the translators for the extra work. Each translated
tiddler type needs a new “group” field that contains a locale-specific
group name that in English are “Image”, “Developer” and “Text”.

core/language/en-GB/Types/application_json.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/application/json
 description: JSON data
 name: application/json
+group: Developer

core/language/en-GB/Types/application_x_tiddler_dictionary.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/application/x-tiddler-dictionary
 description: Data dictionary
 name: application/x-tiddler-dictionary
+group: Developer

core/language/en-GB/Types/image_gif.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/image/gif
 description: GIF image
 name: image/gif
+group: Image

core/language/en-GB/Types/image_jpeg.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/image/jpeg
 description: JPEG image
 name: image/jpeg
+group: Image

core/language/en-GB/Types/image_png.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/image/png
 description: PNG image
 name: image/png
+group: Image

core/language/en-GB/Types/image_svg_xml.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/image/svg+xml
 description: Structured Vector Graphics image
 name: image/svg+xml
+group: Image

core/language/en-GB/Types/image_x-icon.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/image/x-icon
 description: ICO format icon file
 name: image/x-icon
+group: Image

core/language/en-GB/Types/text_css.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/text/css
 description: Static stylesheet
 name: text/css
+group: Developer

core/language/en-GB/Types/text_html.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/text/html
 description: HTML markup
 name: text/html
+group: Text

core/language/en-GB/Types/text_plain.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/text/plain
 description: Plain text
 name: text/plain
+group: Text

core/language/en-GB/Types/text_vnd.tiddlywiki.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/text/vnd.tiddlywiki
-description: TiddlyWiki version 5 wikitext
+description: TiddlyWiki 5
 name: text/vnd.tiddlywiki
+group: Text

core/language/en-GB/Types/text_x-tiddlywiki.tid

@@ -1,3 +1,4 @@
 title: $:/language/Docs/Types/text/x-tiddlywiki
-description: TiddlyWiki Classic wikitext
+description: TiddlyWiki Classic
 name: text/x-tiddlywiki
+group: Text