Add Blender Conference 2023 to the website

For the hands-on class, there will be a special build of Flamenco. It
disables Shaman on all platforms (for uniformity for all participants)
and hard-codes `localhost` as URL for the Workers (to prevent
participants' Workers from finding each other's Managers).

The special build of Flamenco will be done on a separate branch
(`bcon-2023`), but the website should stay for longer, and thus this
commit is on the `main` branch.

web/project-website/content/bcon23/_index.md

@@ -0,0 +1,39 @@
+---
+title: Blender Conference 2023
+weight: 100
+
+geekdocAnchor: false
+geekdocBreadcrumb: false
+geekdocCollapseSection: true
+geekdocHidden: true
+geekdocNav: false
+---
+
+{{< columns >}}
+
+# Free & Open Source <br> Render Management
+
+Here you can download the files for the [**Blender Conference Hands-On Class on Flamenco v3.3**][schedule].
+
+[schedule]: https://conference.blender.org/2023/presentations/1862/
+
+## 1. Download the blend file
+
+{{< button class="btn-secondary" size="large" href="/downloads/flamenco-bcon23-demo.blend" >}}Download BCON23 Demo Blend File{{< /button >}}
+
+<p><!-- weirdly necessary for spacing while inside a <columns> --></p>
+
+## 2. Download the Flamenco package
+
+<table>
+<tr><th> Platform</th><th>File                                                </th></tr>
+<tr><td> Windows </td><td>{{< flamenco/downloadLink version="3.3-bcon23" os="windows" ext="zip" >}}</td></tr>
+<tr><td> Linux   </td><td>{{< flamenco/downloadLink version="3.3-bcon23" os="linux" >}}            </td></tr>
+<tr><td> macOS   </td><td>{{< flamenco/downloadLink version="3.3-bcon23" os="macos" >}}            </td></tr>
+</table>
+
+<--->
+
+![BCon Banner](bcon-banner.webp)
+
+{{</ columns >}}

web/project-website/layouts/shortcodes/flamenco/downloadLink.html

@@ -1,5 +1,6 @@
 {{- $os := .Get "os" | default "linux" -}}
 {{- $arch := .Get "arch" | default "amd64" -}}
 {{- $extension := .Get "ext" | default "tar.gz" -}}
-{{- $filename := printf "flamenco-%s-%s-%s.%s" $.Site.Data.flamenco.latestVersion $os $arch $extension -}}
+{{- $version := .Get "version" | default $.Site.Data.flamenco.latestVersion -}}
+{{- $filename := printf "flamenco-%s-%s-%s.%s" $version $os $arch $extension -}}
 <a class="flamenco-download-link" href="/downloads/{{ $filename }}">{{ $filename }}</a>