Fix DOCX headings, captions and page breaks; polish PPTX layout

- docx: zero paragraph indent for centered headings/captions/figure notes
  so they no longer shift right (empty <w:ind/> inherited 709 twips)
- docx: use pageBreakBefore instead of a separate break paragraph; drop
  the merger page break to remove the blank page after the title page
- docx: heading numbers separated by space instead of tab
- docx: bullet marker is the Symbol dash U+F02D
- pptx: narrower slide number moved left and bold; content title lower;
  section title on the right half like title/final

pptx/src/config.js

@@ -30,11 +30,12 @@ const DEFAULTS = {
     },
     slideNumber: {
       show: true,
-      x: 12.05,
+      x: 11.7,
       y: 6.86,
-      w: 1.15,
+      w: 0.8,
       h: 0.42,
       fontSize: 12,
+      bold: true,
       color: "FFFFFF",
       align: "right",
     },
@@ -46,10 +47,10 @@ const DEFAULTS = {
       body: { x: 6.7, y: 4.65, w: 5.95, h: 1.7, fontSize: 14, align: "center", color: "white" },
     },
     section: {
-      title: { x: 2.0, y: 2.85, w: 9.35, h: 1.8, fontSize: 32, bold: true, align: "center", color: "white" },
+      title: { x: 6.7, y: 2.85, w: 5.95, h: 1.8, fontSize: 32, bold: true, align: "center", color: "white" },
     },
     content: {
-      title: { x: 0.6, y: 0.06, w: 12.15, h: 0.66, fontSize: 20, bold: false, align: "center", color: "white" },
+      title: { x: 0.6, y: 0.14, w: 12.15, h: 0.7, fontSize: 22, bold: false, align: "center", valign: "middle", color: "white" },
       body: { x: 0.75, y: 1.0, w: 11.85, h: 5.55, fontSize: 18, align: "left", color: "ink", valign: "top" },
       bulletSize: 18,
       subBulletSize: 16,