Inject automatically on install etc., add mime types, and fix nits.

go-back-with-backspace/readme.txt

Index: go-back-with-backspace/readme.txt
diff --git a/go-back-with-backspace/readme.txt b/go-back-with-backspace/readme.txt
index 8f94359a8286dc4d5b07db06a5e25d6e66aae5d0..cf09e3e20c97705757e3ea31fdf3cad85ef15d54 100644
--- a/go-back-with-backspace/readme.txt
+++ b/go-back-with-backspace/readme.txt
@@ -6,15 +6,20 @@ text). Many people lost their progress while working online by accidentally
 pressing backspace and leaving a page -- so we removed the feature from Chrome,
 and created this extension for those who prefer the old behavior.
 
-After this extension is newly installed, enabled, or updated, any open tabs
-will need to be reloaded for the changes to take effect.
-
 This extension can't restore backspace on certain special pages, for example
-any of the "chrome://" pages such as Settings or Extensions.
+any of the "chrome://" pages such as Settings or Extensions, or in the Chrome
+Web Store.
+
+About the requested permissions:
+
+"Read and modify all your data": In order to capture backspace on every page,
+the extension needs to install a little piece of code on each one, including
+tabs that are already open when the extension itself is installed or updated.
+It does nothing else with the page, its information, or your typing.
 
-About the "all sites" permission: In order to capture backspace on every page,
-the extension needs to install a little piece of code on each one. It does
-nothing else with the the page, its information, or your typing.
+"Manage your apps, extensions, and themes": This lets the extension detect
+when it has been re-enabled and install its code into tabs that are already
+open then, too.
 
 By installing this item, you agree to the Google Terms of Service and Privacy
 Policy at https://www.google.com/intl/en/policies/.