Add text-decoration-line: spelling-error and grammar-error feature (#3846)

Suggested-By: https://github.com/web-platform-dx/web-features/pull/3841/changes#r2894663729
Co-authored-by: Patrick Brosset <patrickbrosset@gmail.com>

Author: ddbeck

features/text-decoration-spelling-grammar.yml

@@ -0,0 +1,7 @@
+name: Spelling and grammar text decorations
+description: >
+  The `text-decoration-line: spelling-error` and `text-decoration-line: grammar-error` CSS declarations apply the browser's marking for spelling and grammatical mistakes. This is typically a wavy underline in red or green.
+spec: https://drafts.csswg.org/css-text-decor-4/#valdef-text-decoration-line-spelling-error
+compat_features:
+  - css.properties.text-decoration-line.grammar-error
+  - css.properties.text-decoration-line.spelling-error

features/text-decoration-spelling-grammar.yml.dist

@@ -0,0 +1,17 @@
+# Generated from: text-decoration-spelling-grammar.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: low
+  baseline_low_date: 2025-12-12
+  support:
+    chrome: "121"
+    chrome_android: "121"
+    edge: "121"
+    firefox: "137"
+    firefox_android: "137"
+    safari: "26.2"
+    safari_ios: "26.2"
+compat_features:
+  - css.properties.text-decoration-line.grammar-error
+  - css.properties.text-decoration-line.spelling-error

features/text-decoration.yml

@@ -8,11 +8,9 @@ compat_features:
   - css.properties.text-decoration
   - css.properties.text-decoration-color
   - css.properties.text-decoration-line
-  - css.properties.text-decoration-line.grammar-error
   - css.properties.text-decoration-line.line-through
   - css.properties.text-decoration-line.none
   - css.properties.text-decoration-line.overline
-  - css.properties.text-decoration-line.spelling-error
   - css.properties.text-decoration-line.underline
   - css.properties.text-decoration-skip
   - css.properties.text-decoration-skip.auto

features/text-decoration.yml.dist

@@ -99,19 +99,6 @@ compat_features:
   #   safari_ios: "26.2"
   - css.properties.text-decoration.includes_thickness
 
-  # baseline: low
-  # baseline_low_date: 2025-12-12
-  # support:
-  #   chrome: "121"
-  #   chrome_android: "121"
-  #   edge: "121"
-  #   firefox: "137"
-  #   firefox_android: "137"
-  #   safari: "26.2"
-  #   safari_ios: "26.2"
-  - css.properties.text-decoration-line.grammar-error
-  - css.properties.text-decoration-line.spelling-error
-
   # baseline: false
   # support:
   #   safari: "12.1"