chore: stop editors from trimming README's markdown line breaks

README.md relies on two trailing spaces per line in its WordPress
readme header block to force Markdown line breaks. Exempt *.md from
trim_trailing_whitespace in .editorconfig, and add the same exemption
to VS Code's own files.trimTrailingWhitespace setting since it can
override .editorconfig without the EditorConfig extension.

Author: torounit

.editorconfig

@@ -17,3 +17,6 @@ indent_style = tab
 indent_style = space
 indent_size = 2
 
+[*.md]
+trim_trailing_whitespace = false
+

.vscode/settings.json

@@ -0,0 +1,5 @@
+{
+	"[markdown]": {
+		"files.trimTrailingWhitespace": false
+	}
+}