chore(markdown): Restructuring dev docs

markdown/dev/reference/api/settings/margin/en.md

@@ -0,0 +1,31 @@
+--- 
+title: margin
+---
+
+Allows you to specify a part margin (in mm). The default is 2mm.  
+Each part will have this margin applied. This means that:
+
+ - At the edge of the SVG, the margin will be `margin * 1` (2mm by default)
+ - Between parts, the margin will be `margin * 2` (4mm by default)
+ 
+Note that setting the margin to zero (or below) will cause parts to overlap.
+
+```js
+import brian from "@freesewing/brian";
+
+let pattern = new brian({
+  margin: 5
+})
+```
+
+<Note>
+
+###### For paperless, the minimal margin is 10mm
+
+In paperless mode, the margin will not go below 10mm. 
+
+That is because text is not taken into account when calculating the bounding box of the part.
+Since dimensions are typically the outermost elements in a paperless part, 
+a too narrow margin would cause the dimension text to get cut off.
+
+</Note>