Bugfix/31 anchor name formatting amends

[i-just]

Description

1. Adds decoding of special chars before generating anchor names.

Example:

{{ tag('h2', {
    text: "We'd love to hear from you",
})|anchors }}

was producing an anchor of: we-039-d-love-to-hear-from-you, while {% apply anchors() %} and |anchors were producing: wed-love-to-hear-from-you.

Now all 3 options produce: wed-love-to-hear-from-you.

2. Adds lowercase attribute, which defaults to false and produces the same behaviour as before. If set to true, it ensures that the entire anchor is lowercase.
   The default behaviour stays as is: lowercase words that are all uppercase and lowercase the first letter in any other case.

Example:

{% apply anchors('h2') %}
    <h2>Pitch FAQs</h2>
{% endapply %}

still produces: pitch-fAQs

{% apply anchors('h2', lowercase=true) %}
    <h2>Pitch FAQs</h2>
{% endapply %}

produces: pitch-faqs

Applies to v2 and v3.

@brandonkelly if you think point 2 is not something we should pursue or it should be changed to a configuration setting, please let me know, and I’ll adjust. I’m thinking this version gives the best flexibility.

Related issues

#31