Avoid removing backslashes from Dockerfiles

foxundermoon/vs-shell-format#29
foxundermoon/vs-shell-format#62
mvdan/sh#424

The foxundermoon/vs-shell-format extension formats Dockerfiles, but it
shouldn't, because the underlying formatter mvdan/sh isn't engineered
for Dockerfiles. As explained in mvdan/sh#424,

> Removing the `\` is correct in shell, because a line ending in `&&`
> just continues the command in the following line.

This commit will disable Dockerfile formatting.

codium/User/settings.json

@@ -95,7 +95,7 @@
  "cSpell.spellCheckDelayMs": 5000,
  "deno.unstable": false,
  "[dockerfile]": {
- "editor.defaultFormatter": "foxundermoon.shell-format"
+ "editor.formatOnSave": false
  },
  "[dotenv]": {
  "editor.defaultFormatter": "foxundermoon.shell-format"
@@ -150,6 +150,7 @@
  "editor.rulers": [80],
  "files.eol": "\n"
  },
+ "shellformat.effectLanguages": ["shellscript"],
  "[typescript]": {
  "editor.defaultFormatter": "esbenp.prettier-vscode"
  },