Add onboarding flow using Reactour (#4635)

# Description of Changes
Add onboarding flow

frontend/public/locales/en-GB/translation.json

@@ -94,8 +94,8 @@
   "save": "Save",
   "saveToBrowser": "Save to Browser",
   "download": "Download",
-  "pin": "Pin",
-  "unpin": "Unpin",
+  "pin": "Pin File (keep active after tool run)",
+  "unpin": "Unpin File (replace after tool run)",
   "undoOperationTooltip": "Click to undo the last operation and restore the original files",
   "undo": "Undo",
   "moreOptions": "More Options",
@@ -455,6 +455,9 @@
     "alphabetical": "Alphabetical",
     "globalPopularity": "Global Popularity",
     "sortBy": "Sort by:",
+    "mobile": {
+      "brandAlt": "Stirling PDF logo"
+    },
     "multiTool": {
       "tags": "multiple,tools",
       "title": "PDF Multi Tool",
@@ -3469,6 +3472,7 @@
     "automate": "Automate",
     "files": "Files",
     "activity": "Activity",
+    "help": "Help",
     "account": "Account",
     "config": "Config",
     "allTools": "All Tools"
@@ -3969,5 +3973,38 @@
   "undoQuotaError": "Cannot undo: insufficient storage space",
   "undoStorageError": "Undo completed but some files could not be saved to storage",
   "undoSuccess": "Operation undone successfully",
-  "unsupported": "Unsupported"
+  "unsupported": "Unsupported",
+  "onboarding": {
+    "welcomeModal": {
+      "title": "Welcome to Stirling PDF!",
+      "description": "Would you like to take a quick 1-minute tour to learn the key features and how to get started?",
+      "helpHint": "You can always access this tour later from the <strong>Help</strong> button in the bottom left.",
+      "startTour": "Start Tour",
+      "maybeLater": "Maybe Later",
+      "dontShowAgain": "Don't Show Again"
+    },
+    "allTools": "This is the <strong>All Tools</strong> panel, where you can browse and select from all available PDF tools.",
+    "selectCropTool": "Let's select the <strong>Crop</strong> tool to demonstrate how to use one of the tools.",
+    "toolInterface": "This is the <strong>Crop</strong> tool interface. As you can see, there's not much there because we haven't added any PDF files to work with yet.",
+    "filesButton": "The <strong>Files</strong> button on the Quick Access bar allows you to upload PDFs to use the tools on.",
+    "fileSources": "You can upload new files or access recent files from here. For the tour, we'll just use a sample file.",
+    "workbench": "This is the <strong>Workbench</strong> - the main area where you view and edit your PDFs.",
+    "viewSwitcher": "Use these controls to select how you want to view your PDFs.",
+    "viewer": "The <strong>Viewer</strong> lets you read and annotate your PDFs.",
+    "pageEditor": "The <strong>Page Editor</strong> allows you to do various operations on the pages within your PDFs, such as reordering, rotating and deleting.",
+    "activeFiles": "The <strong>Active Files</strong> view shows all of the PDFs you have loaded into the tool, and allows you to select which ones to process.",
+    "fileCheckbox": "Clicking one of the files selects it for processing. You can select multiple files for batch operations.",
+    "selectControls": "The <strong>Right Rail</strong> contains buttons to quickly select/deselect all of your active PDFs, along with buttons to change the app's theme or language.",
+    "cropSettings": "Now that we've selected the file we want crop, we can configure the Crop tool to choose the area that we want to crop the PDF to.",
+    "runButton": "Once the tool has been configured, this button allows you to run the tool on all the selected PDFs.",
+    "results": "After the tool has finished running, the <strong>Review</strong> step will show a preview of the results in this panel, and allow you to undo the operation or download the file. ",
+    "fileReplacement": "The modified file will replace the original file in the Workbench automatically, allowing you to easily run it through more tools.",
+    "pinButton": "You can use the <strong>Pin</strong> button if you'd rather your files stay active after running tools on them.",
+    "wrapUp": "You're all set! You've learnt about the main areas of the app and how to use them. Click the <strong>Help</strong> button whenever you like to see this tour again.",
+    "previous": "Previous",
+    "next": "Next",
+    "finish": "Finish",
+    "startTour": "Start Tour",
+    "startTourDescription": "Take a guided tour of Stirling PDF's key features"
+  }
 }