Update changelog and small doc fixes

Changelog.md

@@ -2,7 +2,7 @@
 
 ## v0.6.0
 
-*Unknown*
+*May 25th, 2020*
 
 - New feature "Scan Mailboxes". Docspell can now read mailboxes
   periodically to import your mails.

modules/microsite/docs/doc/tools/browserext.md

@@ -12,18 +12,18 @@ application that pushes it to docspell. There is a browser add-on
 implementing this in `tools/webextension`. This add-on only works with
 firefox.
 
-### Install
+## Install
 
 This is a bit complicated, since you need to install external tools
 and the web extension. Both work together.
 
-#### Install `ds.sh`
+### Install `ds.sh`
 
 First copy the `ds.sh` tool somewhere in your `PATH`, maybe
 `/usr/local/bin` as described above.
 
 
-#### Install the native part
+### Install the native part
 
 Then install the "native" part of the web extension:
 
@@ -54,7 +54,7 @@ the tool. Or create a file `$HOME/.config/docspell/ds.cmd` whose
 content is the path to the `ds.sh` script.
 
 
-#### Install the extension
+### Install the extension
 
 An extension file can be build using the `make-xpi.sh` script. But
 installing it in "standard" firefox won't work, because [Mozilla

modules/microsite/docs/doc/tools/ds.md

@@ -28,7 +28,7 @@ The key must start with `url`. The urls should be [anonymous upload
 urls](./uploading#anonymous-upload).
 
 
-### Usage
+## Usage
 
 - The `-c` option allows to specifiy a different config file.
 - The `-h` option shows a help overview.