project: drop some recommended extensions aws#1862

These extensions are not particularly related to this project,
developers should install whatever they prefer for typescript/npm work.

Also markdownlint makes recommendations that are not necessarily aligned
with our build tooling. Furthermore it is redundant, because our build
lints itself, and prettier autoformats at commit-time.

Author: justinmk3

.vscode/extensions.json

@@ -1,12 +1,5 @@
 {
     // See http://go.microsoft.com/fwlink/?LinkId=827846
     // for the documentation about the extensions.json format
-    "recommendations": [
-        "christian-kohler.npm-intellisense",
-        "christian-kohler.path-intellisense",
-        "davidanson.vscode-markdownlint",
-        "dbaeumer.vscode-eslint",
-        "eg2.vscode-npm-script",
-        "ms-python.python"
-    ]
+    "recommendations": ["dbaeumer.vscode-eslint", "eg2.vscode-npm-script"]
 }