update tooltips to use sentence case

bigbluebutton-html5/private/locales/en.json

 {
     "app.home.greeting": "Your presentation will begin shortly...",
-    "app.chat.submitLabel": "Send Message",
+    "app.chat.submitLabel": "Send message",
     "app.chat.errorMinMessageLength": "The message is {0} characters(s) too short",
     "app.chat.errorMaxMessageLength": "The message is {0} characters(s) too long",
     "app.chat.inputLabel": "Message input for chat {0}",
@@ -11,7 +11,7 @@
     "app.chat.closeChatLabel": "Close {0}",
     "app.chat.hideChatLabel": "Hide {0}",
     "app.chat.moreMessages": "More messages below",
-    "app.chat.dropdown.options": "Chat Options",
+    "app.chat.dropdown.options": "Chat options",
     "app.chat.dropdown.clear": "Clear",
     "app.chat.dropdown.copy": "Copy",
     "app.chat.dropdown.save": "Save",
@@ -39,7 +39,7 @@
     "app.userList.userAriaLabel": "{0} {1} {2}  Status {3}",
     "app.userList.menu.promoteUser.label": "Promote to moderator",
     "app.userList.menu.demoteUser.label": "Demote to viewer",
-    "app.userList.userOptions.manageUsersLabel": "Manage Users",
+    "app.userList.userOptions.manageUsersLabel": "Manage users",
     "app.userList.userOptions.muteAllLabel": "Mute all users",
     "app.userList.userOptions.muteAllDesc": "Mutes all users in the meeting",
     "app.userList.userOptions.clearAllLabel": "Clear all status icons",
@@ -73,7 +73,7 @@
     "app.presentation.presentationToolbar.zoomOutLabel": "Zoom out",
     "app.presentation.presentationToolbar.zoomOutDesc": "Zoom out of the presentation",
     "app.presentation.presentationToolbar.zoomIndicator": "Show the zoom percentage",
-    "app.presentation.presentationToolbar.fitToWidth": "Fit to Width",
+    "app.presentation.presentationToolbar.fitToWidth": "Fit to width",
     "app.presentation.presentationToolbar.goToSlide": "Slide {0}",
     "app.presentationUploder.title": "Presentation",
     "app.presentationUploder.message": "As a presenter in BigBlueButton, you have the ability of uploading any office document or PDF file. We recommend for the best results, to please upload a PDF file.",
@@ -135,7 +135,7 @@
     "app.navBar.settingsDropdown.hotkeysDesc": "Listing of available hotkeys",
     "app.navBar.settingsDropdown.helpLabel": "Help",
     "app.navBar.settingsDropdown.helpDesc": "Links user to video tutorials",
-    "app.navBar.userListToggleBtnLabel": "User List Toggle",
+    "app.navBar.userListToggleBtnLabel": "User list toggle",
     "app.navBar.toggleUserList.ariaLabel": "Users and Messages Toggle",
     "app.navBar.toggleUserList.newMessages": "with new message notification",
     "app.navBar.recording": "This session is being recorded",
@@ -167,8 +167,8 @@
     "app.submenu.application.audioAlertLabel": "Audio Alerts for Chat",
     "app.submenu.application.pushAlertLabel": "Popup Alerts for Chat",
     "app.submenu.application.fontSizeControlLabel": "Font size",
-    "app.submenu.application.increaseFontBtnLabel": "Increase Application Font Size",
-    "app.submenu.application.decreaseFontBtnLabel": "Decrease Application Font Size",
+    "app.submenu.application.increaseFontBtnLabel": "Increase application font size",
+    "app.submenu.application.decreaseFontBtnLabel": "Decrease application font size",
     "app.submenu.application.languageLabel": "Application Language",
     "app.submenu.application.ariaLanguageLabel": "Change Application Language",
     "app.submenu.application.languageOptionLabel": "Choose language",
@@ -315,8 +315,8 @@
     "app.audioManager.requestTimeout": "Error: There was a timeout in the request",
     "app.audioManager.invalidTarget": "Error: Tried to request something to an invalid target",
     "app.audioManager.mediaError": "Error: There was an issue getting your media devices",
-    "app.audio.joinAudio": "Join Audio",
-    "app.audio.leaveAudio": "Leave Audio",
+    "app.audio.joinAudio": "Join audio",
+    "app.audio.leaveAudio": "Leave audio",
     "app.audio.enterSessionLabel": "Enter Session",
     "app.audio.playSoundLabel": "Play Sound",
     "app.audio.backLabel": "Back",
@@ -443,8 +443,8 @@
     "app.whiteboard.toolbar.color.violet": "Violet",
     "app.whiteboard.toolbar.color.magenta": "Magenta",
     "app.whiteboard.toolbar.color.silver": "Silver",
-    "app.whiteboard.toolbar.undo": "Undo Annotation",
-    "app.whiteboard.toolbar.clear": "Clear All Annotations",
+    "app.whiteboard.toolbar.undo": "Undo annotation",
+    "app.whiteboard.toolbar.clear": "Clear all annotations",
     "app.whiteboard.toolbar.multiUserOn": "Turn multi-user mode on",
     "app.whiteboard.toolbar.multiUserOff": "Turn multi-user mode off",
     "app.whiteboard.toolbar.fontSize": "Font Size List",