add details for JiK and XiK

Author: zkat

src/_includes/partials/compatibility-with-json-and-xml.md

@@ -0,0 +1,14 @@
+<section class="kdl-section" id="compatibility-with-json-and-xml">
+
+## Compatibility with JSON and XML
+
+There are two specifications for writing KDL that can be losslessly translated
+between it and JSON or XML. These specifications define a stricter _subset_ of
+KDL that, even if not entirely idiomatic, is still valid and fits into the
+data models of the other two languages:
+
+* [JSON in KDL](https://github.com/kdl-org/kdl/blob/main/JSON-IN-KDL.md)
+* [XML in KDL](https://github.com/kdl-org/kdl/blob/main/XML-IN-KDL.md)
+
+</section>
+

src/_includes/partials/faq.md

@@ -2,14 +2,10 @@
 
 ## FAQ
 
-#### How do you pronounce "KDL"?
+#### How do you pronounce KDL?
 
 Same as "cuddle".
 
-#### What is the expected file extension?
-
-A file containing KDL should end with `.kdl`.
-
 #### Why yet another document language?
 
 Because nothing out there felt quite right. The closest one I found was
@@ -68,6 +64,10 @@ forgiving syntax without being so flexible as to allow certain classes of
 unfortunate mistakes. It also has much more flexibility around how to
 represent data.
 
+If you need to interoperate with a service that consumes or emits JSON, or for
+some other reason have need to write "JSON in KDL", [we have JiK, an official
+microsyntax for losslessly encoding JSON](https://github.com/kdl-org/kdl/blob/main/JSON-IN-KDL.md).
+
 #### What about TOML?
 
 It nests very poorly. It doesn't fare well with large files.
@@ -95,4 +95,9 @@ Finally, KDL is **not** a markup language. XML or HTML do a much better job of
 useful for templating engines that want to be more strict about text
 fragments.
 
+If you need to interoperate with a service that consumes or emits XML, or for
+some other reason have need to write "XML in KDL", [we have XiK, an official
+microsyntax for losslessly encoding XML](https://github.com/kdl-org/kdl/blob/main/XML-IN-KDL.md).
+
+
 </section>

src/index.md

@@ -13,4 +13,5 @@ title: The KDL Document Language
 {% include partials/implementations.md %}
 {% include partials/design-and-discussion.md %}
 {% include partials/design-principles.md %}
+{% include partials/compatibility-with-json-and-xml %}
 {% include partials/faq.md %}