Blank parsoid styles, update thumbnail selectors for Parsoid content

This brings Parsoid styles when viewed in Minerva consistent with
MediaWiki parser output styles.

You can verify this with:
https://gerrit.wikimedia.org/r/#/c/368287/

Bug: T171727
Change-Id: If4bd7671a99aefdf074061dd1d5b0bac93620e9e

resources/skins.minerva.content.styles/thumbnails.less

@@ -13,6 +13,7 @@
 //
 // Styleguide 1.2.
 .content {
+	figure,
 	.thumb {
 		margin: 0.6em 0;
 
@@ -24,12 +25,16 @@
 		}
 	}
 
+	figcaption,
 	.thumbcaption {
 		margin: 0.5em 0 0;
 		font-size: 0.8em;
 		line-height: 1.5;
 		padding: 0 !important;
 		color: @grayMediumDark;
+	}
+
+	.thumbcaption {
 		width: auto !important;
 	}
 

resources/skins.minerva.tablet.styles/common.less

@@ -90,7 +90,11 @@ A file for css that optimises the Minerva skin on larger devices.
 		// e.g. [[File:Scholars mate animation.gif|frame|left|"[[Scholar's mate]]"]]
 		// We use @noflip because we still want .tleft to be on the left and
 		// .tright to be on the right in RTL languages.
+		figure,
 		.thumb {
+			width: 320px;
+
+			&.mw-halign-left,
 			&.tleft {
 				/* @noflip */
 				float: left;
@@ -100,6 +104,8 @@ A file for css that optimises the Minerva skin on larger devices.
 				margin-right: 1.4em;
 			}
 
+			&.mw-default-size,
+			&.mw-halign-right,
 			&.tright {
 				/* @noflip */
 				float: right;

skin.json

@@ -36,6 +36,7 @@
 	},
 	"ResourceModuleSkinStyles": {
 		"minerva": {
+			"mediawiki.skinning.content.parsoid": [],
 			"mediawiki.hlist": [
 				"skinStyles/mediawiki.hlist/minerva.less"
 			],