Clean up spec metadata (#464)

* Wanming Lin (@Honry) is not working on sensors anymore, so remove the Test
  Facilitator entry.
* Remove the Ignored Vars entry, it does not have any effect at the moment,
  and the currently recommended way of achieving the same thing is to use
  `<var ignore>`.
* Remove the Boilerplate entry, there is no reason to omit the items we were
  omitting there (and some of them did not have any effect anyway):
  - Stop omitting the Conformance section, which allows us to remove the
    hand-written version we currently have as well. While at it, remove the
    extra Conformance Classes section, which defines "conformant user agent"
    without exporting it or ever referencing the term. It looks superfluous
    anyway.
  - Stop setting repository-issue-tracking to "no", which allows us to get
    rid of the Issue Tracking metadata entry.

index.bs

@@ -10,22 +10,18 @@ Editor: Rick Waldron 50572, Invited Expert, formerly on behalf of Bocoup and
 Former Editor: Mikhail Pozdnyakov 78325, Intel Corporation, https://intel.com/
 Former Editor: Alexander Shalamov 78335, Intel Corporation, https://intel.com/
 Former Editor: Tobie Langel 60809, Codespeaks, formerly on behalf of Intel Corporation, https://www.codespeaks.com/, tobie@codespeaks.com
-!Test Facilitator: Wanming Lin (Intel Corporation)
 Abstract:
   This specification defines a framework for exposing sensor data
   to the Open Web Platform in a consistent way.
   It does so by defining a blueprint for writing
   specifications of concrete sensors along with an abstract Sensor interface
   that can be extended to accommodate different sensor types.
-Issue Tracking: Generic Sensor API Issues Repository https://github.com/w3c/sensors/issues
 !Other: <a href="https://github.com/web-platform-tests/wpt/tree/master/generic-sensor">Test suite</a>, <a href="https://github.com/w3c/sensors/commits/main/index.bs">latest version history</a>, <a href="https://github.com/w3c/sensors/commits/gh-pages/index.bs">previous version history</a>
 Indent: 2
 Repository: w3c/sensors
 Markup Shorthands: markdown on
-Boilerplate: omit issues-index, omit conformance, omit feedback-header, repository-issue-tracking no
 Include MDN Panels: if possible
 Implementation Report: https://www.w3.org/wiki/DAS/Implementations
-Ignored Vars: activated_sensors
 Inline GitHub Issues: yes
 Default Biblio Status: current
 Status Text:
@@ -2264,60 +2260,6 @@ and
 Michael[tm] Smith
 for their editorial input.
 
-<h2 id="conformance" class="no-ref no-num">Conformance</h2>
-
-<h3 id="conventions" class="no-ref no-num">Document conventions</h3>
-
-    <p>Conformance requirements are expressed with a combination of
-    descriptive assertions and RFC 2119 terminology. The key words "MUST",
-    "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT",
-    "RECOMMENDED", "MAY", and "OPTIONAL" in the normative parts of this
-    document are to be interpreted as described in RFC 2119.
-    However, for readability, these words do not appear in all uppercase
-    letters in this specification.
-
-    <p>All of the text of this specification is normative except sections
-    explicitly marked as non-normative, examples, and notes. [[!RFC2119]]</p>
-
-    <p>Examples in this specification are introduced with the words "for example"
-    or are set apart from the normative text with <code>class="example"</code>,
-    like this:
-
-    <div class="example">
-        <p>This is an example of an informative example.</p>
-    </div>
-
-    <p>Because this document doesn't itself define APIs for specific [=sensor types=]--
-    that is the role of extensions to this specification--
-    all examples are inevitably (wishful) fabrications.
-    Although all of the [=device sensor|sensors=] used a examples
-    would be great candidates for building atop the Generic Sensor API,
-    their inclusion in this document does not imply that the relevant Working Groups
-    are planning to do so.
-
-    <p>Informative notes begin with the word "Note" and are set apart from the
-    normative text with <code>class="note"</code>, like this:
-
-    <p class="note">Note, this is an informative note.</p>
-
-<h3 id="conformant-algorithms" class="no-ref no-num">Conformant Algorithms</h3>
-
-    <p>Requirements phrased in the imperative as part of algorithms (such as
-    "strip any leading space characters" or "return false")
-    are to be interpreted with the meaning of the key word ("must",
-    "should", "may", etc) used in introducing the algorithm.</p>
-
-    <p>Conformance requirements phrased as algorithms or specific steps can be
-    implemented in any manner, so long as the end result is <dfn>equivalent</dfn>. In
-    particular, the algorithms defined in this specification are intended to
-    be easy to understand and are not intended to be performant. Implementers
-    are encouraged to optimize.</p>
-
-<h3 id="conformance-classes" class="no-ref no-num">Conformance Classes</h3>
-
-    <p>A <dfn>conformant user agent</dfn> must implement all the requirements
-    listed in this specification that are applicable to user agents.</p>
-
 <style>
     #toc .current,
     #toc .current-parent {