Translated the advice on the new 404 error page

Translation of the multi-line/multi-paragraph advice is done under the
assumption that its structure  (5 paragraphs, two of which serve as
entries in a bulleted list) can be preserved in the translations by
proper phrasing, i.e. the advice must be translated as a whole rather
than each of its sentences (which act as units of translation) separately.

static/skin/i18n/en.json

@@ -24,6 +24,11 @@
 	, "new-404-page-heading" : "Oops. Page not found."
 	, "404-img-text": "Not found!"
 	, "path-was-not-found": "The requested path was not found:"
+	, "404-advice.p1": "The content you're looking for may still be available, but it might be located at a different place within the ZIM file."
+	, "404-advice.p2": "Please:"
+	, "404-advice.p3": "Try using the search function to find the content you want"
+	, "404-advice.p4": "Look for keywords or titles related to the information you're seeking"
+	, "404-advice.p5": "This approach should help you locate the desired content, even if the original link isn't working properly."
 	, "500-page-title" : "Internal Server Error"
 	, "500-page-heading" : "Internal Server Error"
 	, "500-page-text": "An internal server error occured. We are sorry about that :/"

static/skin/i18n/qqq.json

@@ -28,6 +28,11 @@
 	"new-404-page-heading": "Heading of the 404 error page",
 	"404-img-text": "Fallback text for the image on the 404 error page",
 	"path-was-not-found": "Message telling that the URL path was not found (to be followed by the actual path)",
+	"404-advice.p1": "1st paragraph of the multiline advice on the 'Page not found' error page (see 404-advice.p1 through 404-advice.p5 for full text)",
+	"404-advice.p2": "2nd paragraph of the multiline advice on the 'Page not found' error page (see 404-advice.p1 through 404-advice.p5 for full text)",
+	"404-advice.p3": "3rd paragraph of the multiline advice on the 'Page not found' error page (see 404-advice.p1 through 404-advice.p5 for full text)",
+	"404-advice.p4": "4th paragraph of the multiline advice on the 'Page not found' error page (see 404-advice.p1 through 404-advice.p5 for full text)",
+	"404-advice.p5": "5th paragraph of the multiline advice on the 'Page not found' error page (see 404-advice.p1 through 404-advice.p5 for full text)",
 	"500-page-title": "Title of the 500 error page",
 	"500-page-heading": "Heading of the 500 error page",
 	"500-page-text": "Text of the 500 error page",

static/skin/i18n/test.json

@@ -17,6 +17,11 @@
 	, "new-404-page-heading" : "[I18N TESTING] Oops. Larry Page could not be reached. He may be on paternity leave."
 	, "404-img-text": "[I18N] Not found! [TESTING]"
 	, "path-was-not-found": "[I18N TESTING] The requested path was not found (in fact, nothing was found instead, either):"
+	, "404-advice.p1": "Sh*t happens. [I18N TESTING] Take it easy!"
+	, "404-advice.p2": "[I18N TESTING] Try one of the following:"
+	, "404-advice.p3": "[I18N TESTING] Check the spelling of the URL path"
+	, "404-advice.p4": "[I18N TESTING] Press the dice button"
+	, "404-advice.p5": "Good luck! [I18N TESTING]"
 	, "library-button-text": "[I18N TESTING] Navigate to the welcome page"
 	, "home-button-text": "[I18N TESTING] Jump to the main page of '{{BOOK_TITLE}}'"
 	, "random-page-button-text": "[I18N TESTING] I am tired of determinism"

static/templates/sexy404.html

@@ -23,13 +23,13 @@
       <p><code>{{url_path}}</code></p>
     </section>
     <section class="advice">
-      <p>The content you're looking for may still be available, but it might be located at a different place within the ZIM file.</p>
-      <p class="list-intro">Please:</p>
+      <p>{{advice.p1}}</p>
+      <p class="list-intro">{{advice.p2}}</p>
       <ul>
-          <li>Try using the search function to find the content you want</li>
-          <li>Look for keywords or titles related to the information you're seeking</li>
+          <li>{{advice.p3}}</li>
+          <li>{{advice.p4}}</li>
       </ul>
-      <p>This approach should help you locate the desired content, even if the original link isn't working properly.</p>
+      <p>{{advice.p5}}</p>
     </section>
   </body>
 </html>