Extend docs to include the download all feature (#1798)

Extend docs to include the download all feature when filtering the documents.

website/site/content/docs/features/_index.md

@@ -22,6 +22,7 @@ template = "docs.html"
   into searchable PDF/A pdfs.
 - A powerful [query language](@/docs/query/_index.md) to find
   documents
+- The possibility to download all the filtered documents (once at least one filter has been selected). 
 - use [bookmarks](@/docs/webapp/bookmarks.md) to save more complex queries
 - customizable [dashboards](@/docs/webapp/dashboards.md) as the main page
 - Non-destructive: all your uploaded files are never modified and can

website/site/content/docs/webapp/download-all.md

@@ -0,0 +1,51 @@
++++
+title = "Download all documents"
+weight = 35
+[extra]
+mktoc = true
++++
+
+# Download all documents
+
+There is a (hidden) option to download all the documents in a filtered view (when you select at least one filter. For example a tag, category, corresponden, etc ...) either as converted PDF files or as original files.
+
+
+## Important (quick-steps)
+
+- You have to go to "Items" (`app/search`)
+- You have to select at least one filter from the left column
+- You have to click on the menu on the top-right (three horizonal lines) -> Download all
+- You Have to select wheter to download the original files or the converted PDF files
+  
+
+## Detailed steps
+
+<div class="flex items-center justify-center">
+  {{ imgnormal2(light="download-all-01.png", dark="download-all-01-dark.png", width="") }}
+</div>
+
+
+1. Go to "Items" (`app/search`) by clicking the docspell logo.
+2. Select at least one filter y clicking them. Once you select a filter the main panel will update itself showing only the documents which match the filters.
+3. Click the top-right menu
+4. Click "Download all"
+
+Once the download panel is open you can select which version of the files you want to download.
+
+<div class="flex items-center justify-center">
+  {{ imgnormal2(light="download-all-02.png", dark="download-all-02-dark.png", width="") }}
+</div>
+
+and the you click on create download
+
+<div class="flex items-center justify-center">
+  {{ imgnormal2(light="download-all-03.png", dark="download-all-03-dark.png", width="") }}
+</div>
+
+and finally you can download the files
+
+<div class="flex items-center justify-center">
+  {{ imgnormal2(light="download-all-04.png", dark="download-all-04-dark.png", width="") }}
+</div>
+
+a ZIP-File will be created will all the selected documents, with a folder structure one folder per month and corresponden folder inside `YYYY-mm/correspondent`.