docs: Change Kinematics.md images to use a solid white background

Avoid transparent backgrounds as they don't render well if there is a
dark background.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

docs/img/trapezoids.svg

@@ -2,20 +2,23 @@
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-   xmlns:svg="http://www.w3.org/2000/svg"
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    viewBox="0 0 344.49789 115.33566"
    id="svg2"
    version="1.1"
-   inkscape:version="0.91 r13725"
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+   sodipodi:docname="trapezoids.svg"
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+   inkscape:export-ydpi="89.734001"
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+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:dc="http://purl.org/dc/elements/1.1/">
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@@ -23,11 +26,11 @@
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      bordercolor="#666666"
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+     inkscape:pageopacity="1"
      inkscape:pageshadow="2"
      inkscape:zoom="2.67"
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-     inkscape:cy="76.011989"
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+     inkscape:cy="76.217228"
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      inkscape:current-layer="layer1"
      showgrid="false"
@@ -42,7 +45,8 @@
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      showborder="false"
      inkscape:snap-global="false"
-     showguides="false">
+     showguides="false"
+     inkscape:pagecheckerboard="0">
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@@ -55,7 +59,6 @@
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-        <dc:title />
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     </rdf:RDF>
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+         y="365.1282"
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