Fix doc typos (.[foo] wanted to be .["foo"])

docs/content/3.manual/manual.yml

@@ -205,11 +205,11 @@ sections:
           - program: '.foo'
             input: '{"notfoo": true, "alsonotfoo": false}'
             output: ['null']
-          - program: '."foo"'
+          - program: '.["foo"]'
             input: '{"foo": 42}'
             output: [42]
 
-      - title: "`.[foo]`, `.[2]`, `.[10:15]`"
+      - title: "`.[<string>]`, `.[2]`, `.[10:15]`"
         body: |
           
           You can also look up fields of an object using syntax like
@@ -254,7 +254,7 @@ sections:
       - title: "`.[]`"
         body: |
           
-          If you use the `.[foo]` syntax, but omit the index
+          If you use the `.[index]` syntax, but omit the index
           entirely, it will return *all* of the elements of an
           array. Running `.[]` with the input `[1,2,3]` will produce the
           numbers as three separate results, rather than as a single