fix broken links and typo

src/pages/_data/navigation/mainNav.json5

@@ -30,7 +30,8 @@
             { title: "Lifecycle Events and Callbacks", url: "/build/callbacks-and-lifecycle-hooks/" },
             { title: "Zome Functions", url: "/build/zome-functions/" },
           ] },
-          { title: "DNAs", url: "/build/dnas/" }
+          { title: "DNAs", url: "/build/dnas/" },
+          { title: "hApps", url: "/build/happs/ },
         ]},
         { title: "Working with Data", url: "/build/working-with-data/", children: [
           { title: "Identifiers", url: "/build/identifiers/" },

src/pages/build/application-structure.md

@@ -10,7 +10,7 @@ title: Application Structure
         * [Lifecycle Events and Callbacks](/build/callbacks-and-lifecycle-hooks/) --- writing functions that respond to events in a hApp's lifecycle
         * [Zome Functions](/build/zome-functions/) --- writing your hApp's back-end API
     * [DNAs](/build/dnas/) --- what they're used for, how to specify and bundle
-    * hApps (coming soon) --- headless vs UI-based, how to bundle and distribute
+    * [hApps](/build/happs/) --- headless vs UI-based, how to bundle and distribute
 :::
 
 ::: intro

src/pages/build/dnas.md

@@ -1,5 +1,5 @@
 ---
-title: "DNA"
+title: "DNAs"
 ---
 
 ::: intro
@@ -68,7 +68,7 @@ coordinator:
             * `bundled`: Expect the file to be part of this [bundle](#bundle-a-dna). The value is a path relative to the manifest file.
             * `path`: Get the file from the local filesystem. The value is a filesystem path.
             * `url`: Get the file from the web. The value is a URL, of course.
-* `coordinator`: Contains all the coordinator bits for the DNA, which do not change the DNA hash and can be modified after the DNA is installed and being used in a [cell](/concepts/2_app_architecture/#cell).
+* `coordinator`: Contains all the coordinator bits for the DNA, which do not change the DNA hash and can be modified after the DNA is installed and being used in a [cell](/concepts/2_application_architecture/#cell).
     * `zomes`: Currently the only field in `coordinator`. A list of coordinator zomes. Each item in the list is the same as in `integrity.zomes` above, except that the following field is added:
         * `dependencies`: The integrity zomes that this coordinator zome depends on. Note that you can leave this field out if there's only one integrity zome (it'll be automatically treated as a dependency). For each dependency in the list, there's one field:
             * `name`: A string matching the `name` field of the integrity zome the coordinator zome depends on.
@@ -120,6 +120,6 @@ Now that you've created a bare DNA, it's time to [fill it with zomes](/build/zom
 
 ## Further reading
 
-* [Get Started: Installing Holochain Development Environment](/get/started/#2-installing-holochain-development-environment)
+* [Get Started: Installing Holochain Development Environment](/get-started/#2-installing-holochain-development-environment)
 * [Core Concepts: Application Architecture](/concepts/2_application_architecture/)
 * [Build Guide: Zomes](/build/zomes/)

src/pages/build/happs.md

@@ -0,0 +1,8 @@
+---
+title: "hApps"
+---
+
+::: intro
+A **hApp** (short for 'Holochain application') is a bundle of one or more [**DNAs**](/build/dnas/), along with an optional web-based user interface. The DNAs in a hApp are a bit like microservices, and all of them together are meant to be installed and instantiated by a single **agent** on each participating user's machine.
+:::
+