Add tooltip to episode filter text edit

src/rss/automatedrssdownloader.cpp

@@ -73,6 +73,16 @@ AutomatedRssDownloader::AutomatedRssDownloader(const QWeakPointer<RssManager>& m
                                  Qt::CaseInsensitive),
                          ui->lineEFilter);
   ui->lineEFilter->setValidator(m_episodeValidator);
+  QString tip = "<p>" + tr("Matches articles based on episode filter.") + "</p><p><b>" + tr("Example: ") +
+                "1x2;8-15;5;30-;</b>" + tr(" will match 2, 5, 8 through 15, 30 and onward episodes of season one", "example X will match") + "</p>";
+  tip += "<p>"  + tr("Episode filter rules: ") + "</p><ul><li>" + tr("Season number is a mandatory non-zero value") + "</li>" +
+         "<li>" + tr("Episode number is a mandatory non-zero value") + "</li>" +
+         "<li>" + tr("Filter must end with semicolon") + "</li>" +
+         "<li>" + tr("Three range types for episodes are supported: ") + "</li>" + "<li><ul>"
+         "<li>" + tr("Single number: <b>1x25;</b> matches episode 25 of season one") + "</li>" +
+         "<li>" + tr("Normal range: <b>1x25-40;</b> matches episodes 25 through 40 of season one") + "</li>" +
+         "<li>" + tr("Infinite range: <b>1x25-;</b> matches 40 and onward episodes of season one") + "</li>" + "</ul></li></ul>";
+  ui->lineEFilter->setToolTip(tip);
   initLabelCombobox();
   loadFeedList();
   loadSettings();