Define examples in the "examples" field instead of "example"

Only examples defined in the "examples" field are generated, if they are
defined in "example", they are just ignored.

Also fix a bunch of incorrect tests.

docs/content/manual/manual.yml

@@ -1721,10 +1721,10 @@ sections:
           Emit a copy of the input string with its alphabetic characters (a-z and A-Z)
           converted to the specified case.
 
-        example:
+        examples:
           - program: 'ascii_upcase'
             input: '"useful but not for é"'
-            output: '"USEFUL BUT NOT FOR é"'
+            output: ['"USEFUL BUT NOT FOR é"']
 
       - title: "`while(cond; update)`"
         body: |
@@ -2500,15 +2500,11 @@ sections:
           To capture all the matches for each input string, use the idiom
           `[ expr ]`, e.g. `[ scan(regex) ]`.
 
-        example:
+        examples:
           - program: 'scan("c")'
             input: '"abcdefabc"'
             output: ['"c"', '"c"']
 
-          - program: 'scan("b")'
-            input: ("", "")
-            output: ['[]', '[]']
-
       - title: "`split(regex; flags)`"
         body: |
 
@@ -2517,10 +2513,10 @@ sections:
           For backwards compatibility, when called with a single argument,
           `split` splits on a string, not a regex.
 
-        example:
+        examples:
           - program: 'split(", *"; null)'
             input: '"ab,cd, ef"'
-            output: ['"ab","cd","ef"']
+            output: ['["ab","cd","ef"]']
 
 
       - title: "`splits(regex)`, `splits(regex; flags)`"
@@ -2529,10 +2525,10 @@ sections:
           These provide the same results as their `split` counterparts,
           but as a stream instead of an array.
 
-        example:
+        examples:
           - program: 'splits(", *")'
-            input: '("ab,cd", "ef, gh")'
-            output: ['"ab"', '"cd"', '"ef"', '"gh"']
+            input: '"ab,cd,   ef, gh"'
+            output: ['"ab"','"cd"','"ef"','"gh"']
 
       - title: "`sub(regex; tostring)`, `sub(regex; tostring; flags)`"
         body: |
@@ -2546,9 +2542,8 @@ sections:
           `tostring`, so a reference to a captured variable named "x"
           would take the form: `"\(.x)"`.
 
-        example:
-
-          - program: 'sub("[^a-z]*(?<x>[a-z]*)"; "Z\(.x)"; "g")'
+        examples:
+          - program: 'sub("[^a-z]*(?<x>[a-z]+)"; "Z\(.x)"; "g")'
             input: '"123abc456def"'
             output: ['"ZabcZdef"']
 
@@ -2563,7 +2558,7 @@ sections:
           replaced by `tostring`, after interpolation. If the second argument is a stream
           of jq strings, then `gsub` will produce a corresponding stream of JSON strings.
 
-        example:
+        examples:
           - program: 'gsub("(?<x>.)[^a]*"; "+\(.x)-")'
             input: '"Abcabc"'
             output: ['"+A-+a-"']