Rename package from 'nw' to 'novelwriter' (#868)

* Rename nw folder to novelwriter
* Rename nw to novelwriter in auxiliary files
* Rename nw to novelwriter in main app source
* Rename nw to novelwriter in tests
* Make setup script for pdf docs less spammy

novelwriter/assets/icons/fallback/search_project-dark.svg

@@ -0,0 +1,31 @@
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+   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"
+   id="svg8301"
+   viewBox="0 0 24 24"
+   height="24"
+   width="24"
+   version="1.2">
+  <metadata
+     id="metadata8307">
+    <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>
+  <defs
+     id="defs8305" />
+  <path
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+</svg>