en-US locale .ftl for Zen-library

Signed-off-by: JustAdumbPrsn <73780892+JustAdumbPrsn@users.noreply.github.com>

locales/en-US/browser/browser/zen-library.ftl

@@ -4,4 +4,23 @@
 
 library-spaces-section-title = Spaces
 library-downloads-section-title = Downloads
-library-history-section-title = History
+library-history-section-title = History
+
+library-search-placeholder = Search…
+library-history-search-placeholder = Search History…
+library-downloads-search-placeholder = Search Downloads…
+
+library-history-today = Today
+library-history-yesterday = Yesterday
+
+library-history-empty = No history found
+library-downloads-empty = No downloads found
+library-spaces-empty = No spaces available
+library-search-no-results = No results
+
+library-filter-button = Filter
+
+library-downloads-state-downloading = Downloading…
+library-downloads-state-canceled = Canceled
+library-downloads-state-failed = Failed
+library-downloads-state-incomplete = Incomplete