address some warnings from yaml lint

Author: davidcarlisle

_data/core-properties.yml

@@ -1,4 +1,3 @@
-
 - property: function
   type: fixity
   applicability: intent function head
@@ -50,8 +49,6 @@
     - intent: "f:silent(x,y)"
       en: "x y"
 
-
-
 - property: literal
   type: inference
   applicability: all presentation elements
@@ -145,32 +142,32 @@
   applicability: mtable
   effect: "the table should be read in a style suitable for displayed equations (and inequations)"
   examples:
-   - mathml: |
-      <mtable intent=':system-of-equations'>
-        <mtr>
-         <mtd columnalign='right'>
-          <mn>2</mn><mo>&#x2062;</mo><mi>x</mi>
-         </mtd>
-         <mtd columnalign='center'>
-          <mo>=</mo>
-         </mtd>
-         <mtd columnalign='left'>
-          <mn>1</mn>
-         </mtd>
-        </mtr>
-        <mtr>
-         <mtd columnalign='right'>
-          <mi>y</mi>
-         </mtd>
-         <mtd columnalign='center'>
-          <mo>></mo>
-         </mtd>
-         <mtd columnalign='left'>
-          <mi>x</mi><mo>&#x2212;</mo><mn>3</mn>
-         </mtd>
-        </mtr>
-       </mtable>
-     en: 2 equations; equation 1; 2 x, is equal to, 1; equation 2; y, is greater than, x minus 3;
+    - mathml: |
+       <mtable intent=':system-of-equations'>
+         <mtr>
+          <mtd columnalign='right'>
+           <mn>2</mn><mo>&#x2062;</mo><mi>x</mi>
+          </mtd>
+          <mtd columnalign='center'>
+           <mo>=</mo>
+          </mtd>
+          <mtd columnalign='left'>
+           <mn>1</mn>
+          </mtd>
+         </mtr>
+         <mtr>
+          <mtd columnalign='right'>
+           <mi>y</mi>
+          </mtd>
+          <mtd columnalign='center'>
+           <mo>></mo>
+          </mtd>
+          <mtd columnalign='left'>
+           <mi>x</mi><mo>&#x2212;</mo><mn>3</mn>
+          </mtd>
+         </mtr>
+        </mtable>
+      en: 2 equations; equation 1; 2 x, is equal to, 1; equation 2; y, is greater than, x minus 3;
 
 
 - property: lines
@@ -274,8 +271,7 @@
       en: 1.5 kilometres
     - mathml: "<mrow><mn>2</mn><mi mathvariant='normal' intent=':unit'>Ω</mi></mrow>"
       en: 2 ohms
-  comment:
-  - "This includes SI units, English units, etc. It also includes radians, degrees, etc."
+  comment: "This includes SI units, English units, etc. It also includes radians, degrees, etc."
 
 - property: currency
   type: units-and-currency
@@ -461,26 +457,27 @@
 - property: use-argname
   type: argname
   applicability: all
-  effect: "Used as a _self-property_ on an element with `arg`, causes the value of the `arg` attribute to be spoken by AT when the user moves to that child. For core concepts, this value should override argument names that would otherwise be used by AT.
+  effect: "Used as a _self-property_ on an element with `arg`, causes the value of the `arg` attribute to be spoken by AT when the user moves to that child.
+           For core concepts, this value should override argument names that would otherwise be used by AT.
            May be translated to the current language, or used literally if translation is not known."
   examples:
-     - mathml: '<mi arg="numerator" intent=":use-argname">x</mi>'
-       en: numerator
-       fr: numérateur
-       de: Zähler
-     - mathml: '<mi arg="denominator" intent=":use-argname">x</mi>'
-       en: denominator
-       fr: dénominateur
-       de: Nenner
-     - mathml: '<mn arg="base" intent=":use-argname">2</mn>'
-       en: base
-       fr: base
-       de: Basis
-     - mathml: '<mrow arg="lower-limit" intent=":use-argname"><mi>i</mi><mo>=</mo><mn>0</mn></mrow>'
-       en: lower-limit
-       fr: "limite à gauche"
-       de: Untergrenze
-     - mathml: '<mi arg="upper-limit" intent=":use-argname">n</mi>'
-       en: upper-limit
-       fr: "limite à droite"
-       de: Obergrenze
+    - mathml: '<mi arg="numerator" intent=":use-argname">x</mi>'
+      en: numerator
+      fr: numérateur
+      de: Zähler
+    - mathml: '<mi arg="denominator" intent=":use-argname">x</mi>'
+      en: denominator
+      fr: dénominateur
+      de: Nenner
+    - mathml: '<mn arg="base" intent=":use-argname">2</mn>'
+      en: base
+      fr: base
+      de: Basis
+    - mathml: '<mrow arg="lower-limit" intent=":use-argname"><mi>i</mi><mo>=</mo><mn>0</mn></mrow>'
+      en: lower-limit
+      fr: "limite à gauche"
+      de: Untergrenze
+    - mathml: '<mi arg="upper-limit" intent=":use-argname">n</mi>'
+      en: upper-limit
+      fr: "limite à droite"
+      de: Obergrenze