Add PicoSSG.dev (#1043)

* Add PicoSSG

PicoSSG is a minimal static site generator that processes markdown, nunjucks templates, and static files into a clean website with no configuration.

* Update repository link, not sure this fixes the invalid syntax

Author: wolframkriesing

src/site/generators/picossg.md

@@ -0,0 +1,19 @@
+---
+title: PicoSSG
+repo: https://codeberg.org/wolframkriesing/picossg
+homepage: https://picossg.dev/
+language:
+  - JavaScript
+license:
+  - AGPL-3.0
+templates:
+  - Nunjucks
+  - HTML
+  - Markdown
+description: The anti-framework static site generator
+---
+
+PicoSSG is a minimal static site generator built on the philosophy of simplicity and predictability. 
+It processes your markdown, nunjucks templates, and static files into a clean, static website with no configuration (unless you need it).
+
+One of PicoSSG's most valuable features is its predictable 1:1 mapping from source to output.