updated devcontainer

.devcontainer/devcontainer.json

@@ -23,7 +23,15 @@
 	"customizations": {
 		// Configure properties specific to VS Code.
 		"vscode": {
-			"settings": {},
+			"settings": {
+				"markdown.marp.enableHtml" : true,
+				"markdown.marp.themes": [
+					"./slides/themes/custom.css",
+					"./slides/themes/custom-default.css",
+					"./slides/themes/custom-gaia.css",
+					"./slides/themes/custom-uncover.css"
+				  ]
+			},
 			"extensions": [
 				"github.vscode-github-actions",
 				"github.vscode-pull-request-github",