don't use markdown-grid-tables, formatting is poor

this extension is adding <p> tags when it shouldn't, and it's pretty
wordy anyway. unfortunately, not using it means that very long cells
have to be on one line, but maybe that's a sign the table is doing too
much work anyway

config.json

@@ -16,8 +16,7 @@
 	},
 	"MARKDOWN_EXTENSIONS": [
 		"extra", "incorporealcms.mdx.figures", "incorporealcms.mdx.pydot",
-		"sane_lists", "smarty", "toc", "attr_list", "tables", "pymdownx.tilde", "md_in_html",
-		"markdown_grid_tables"
+		"sane_lists", "smarty", "toc", "attr_list", "tables", "pymdownx.tilde", "md_in_html"
 	],
 	"MARKDOWN_EXTENSION_CONFIGS": {
 		"extra": {