@posts/PrincipalComponentAnalysis.md; improves

Is followup to: commit a2ffd7c (@`posts/PrincipalComponentAnalysis.md`; `remark-lint`). TODO: `squash` group this

Author: SwuduSusuwu

posts/PrincipalComponentAnalysis.md

@@ -1,5 +1,18 @@
 **[Calculus](https://wikipedia.org/wiki/Calculus) to produce best 2 [orthographic projection](https://wikipedia.org/wiki/Orthographic_projection)s (2D [previews](https://wikipedia.org/wiki/Viewport)) -- of [3D mesh](https://wikipedia.org/wiki/Polygon_mesh)es -- such that you can use projections to do [reconstruction of meshes](https://wikipedia.org/wiki/3D_reconstruction)**
 
+\[[This post](./PrincipalComponentAnalysis.md) \[[<sup>2</sup>](https://swudususuwu.substack.com/p/)\] is [released through *Creative Commons Generic Attribution 2* (which allows all uses)](https://creativecommons.org/licenses/by/2.0/). This post is a work-in-progress, version is [SusuLib@`preview`](https://github.com/SwuduSusuwu/SusuLib/commit/preview)\]
+
+![transform](https://substack-post-media.s3.amazonaws.com/public/images/91f935a9-11e5-41de-b710-5b20e0bdc084_600x300.png)
+\[Attribution: _cover photos (from *Wikipedia*) is included through [Fair Use (publisher for schools).](https://k12irc.org/topics/copyright-and-fair-use/)_\]
+
+
+# Table of Contents
+- [Discussion](#discussion)
+- [Discussion 2](#discussion-2)
+- [Synopsis + similar posts](#synopsis--similar-posts)
+
+******************************************
+# Discussion
 
 \[[This post allows all uses](https://swudususuwu.substack.com/p/formula-to-produce-2-orthographic)\]