Add US Letter size blank template

src/Mod/TechDraw/Templates/USLetter_Landscape_blank.svg

@@ -0,0 +1,67 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   width="279.39999mm"
+   height="215.89999mm"
+   viewBox="0 0 279.40001 215.9"
+   id="svg2"
+   version="1.1"
+   inkscape:version="0.92.3 (2405546, 2018-03-11)"
+   sodipodi:docname="USLetter_Landscape_blank.svg">
+  <!-- Working space 10 10 269 205 -->
+  <defs
+     id="defs4" />
+  <sodipodi:namedview
+     id="base"
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1.0"
+     inkscape:pageopacity="0.0"
+     inkscape:pageshadow="2"
+     inkscape:zoom="0.64460786"
+     inkscape:cx="527.99999"
+     inkscape:cy="470.05322"
+     inkscape:document-units="mm"
+     inkscape:current-layer="svg2"
+     showgrid="false"
+     units="mm"
+     inkscape:window-width="1366"
+     inkscape:window-height="715"
+     inkscape:window-x="0"
+     inkscape:window-y="26"
+     inkscape:window-maximized="1"
+     inkscape:showpageshadow="false"
+     showguides="true"
+     inkscape:guide-bbox="true">
+    <sodipodi:guide
+       position="196.1368,22.514151"
+       orientation="0,1"
+       id="guide4606"
+       inkscape:locked="false" />
+    <sodipodi:guide
+       position="163.68397,54.764151"
+       orientation="1,0"
+       id="guide4608"
+       inkscape:locked="false" />
+  </sodipodi:namedview>
+  <metadata
+     id="metadata7">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title></dc:title>
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+</svg>