Update README

README.md

@@ -2,7 +2,21 @@
 
 # Inkscape extensions for cave surveying
 
-## Installation
+Collection of extensions for Inkscape to import/export various cave mapping data files, including:
+
+| Format                | Import | Export  |
+| --------------------- | ------ | ------- |
+| Survex `.3d`          | Yes    | No      |
+| Therion `.th2`        | Yes    | Yes     |
+| Therion `.xvi`        | Yes    | No      |
+| Therion MetaPost      | No     | Planned |
+| PocketTopo `.top`     | Yes    | No      |
+| SexyTopo `.plan.json` | Yes    | No      |
+
+In addition, there are symbol annotation extensions in the
+_Extensions > Therion_ menu for the `.th2` export.
+
+## Installation (basic)
 
 Copy everything from the [extensions](extensions) folder into the Inkscape extensions folder. This is probably similar to one of these:
 
@@ -11,6 +25,26 @@ Copy everything from the [extensions](extensions) folder into the Inkscape exten
 
 If you can't find the folder, check _Inkscape > Preferences > System > User config_, or run `inkscape --user-data-directory`.
 
+## Installation (advanced)
+
+Clone the repo directly to your user data directory. This can be done (in
+a reasonable safe way) with the following commands:
+
+```sh
+git clone --no-checkout https://github.com/speleo3/inkscape-speleo
+mv inkscape-speleo/.git "$(inkscape --user-data-directory)/"
+rmdir inkscape-speleo
+cd "$(inkscape --user-data-directory)"
+git checkout
+```
+
+And whenever there are updates to the repo:
+
+```sh
+cd "$(inkscape --user-data-directory)"
+git pull
+```
+
 ## See also:
 
 * http://therion.speleo.sk/