feat: Add an example of a picture gallery (#1221)

* feat: Add an example of a picture gallery

* Update rust/pictures-gallery/README.md

Co-authored-by: Jessie Mongeon <133128541+jessiemongeon1@users.noreply.github.com>

---------

Co-authored-by: Jessie Mongeon <133128541+jessiemongeon1@users.noreply.github.com>

Author: raymondk

rust/pictures-gallery/.gitignore

@@ -0,0 +1,25 @@
+# Various IDEs and Editors
+.vscode/
+.idea/
+**/*~
+
+# Mac OSX temporary files
+.DS_Store
+**/.DS_Store
+
+# dfx temporary files
+.dfx/
+
+# generated files
+**/declarations/
+
+# rust
+target/
+
+# frontend code
+node_modules/
+dist/
+.svelte-kit/
+
+# environment variables
+.env