update documentation to include new header.gmi

doc/comitium.1.scd

@@ -112,6 +112,11 @@ Within the data directory, the following files are used:
 	subscription (change its title, update a link, etc) it should be trivial to
 	manually edit.
 
+*header.gmi*
+	This file is neither created nor modified by comitium.  If it exists and is
+	nonempty, then it is read and used as custom header for *feed.gmi*.  If it
+	doesn't exist or is empty, then a default header is used.
+
 *feed.gmi*
 	The outputted text/gemini file containing the subscription items. Is what
 	should be linked or copied to your server directory to publish it.

doc/quickstart.md

@@ -14,6 +14,10 @@ home directory, you can instead find the binary and man page in `build/` after
 running `make`.  You can then copy or symlink `comitium` to your preferred bin
 directory and you can access the man page with `man -l build/comitium.1`.
 
+Prebuilt binraies are also available, but they are x86-64 only and for a limited
+number of operating systems, so it is preferable for you to build it yourself,
+if possible.
+
 [README]: README.md
 
 
@@ -23,7 +27,7 @@ directory and you can access the man page with `man -l build/comitium.1`.
 
 Once you have the binary all set up, you need figure out where you want your
 data directory to be. If you're serving from `~/public_gemini` or something like
-that, then just put `export $COMITIUM_DATA="~/public_gemini"` in your shell's rc
+that, then just put `export COMITIUM_DATA="~/public_gemini"` in your shell's rc
 file and the files will all be set up there.
 
 If you're serving from `/var/gemini` or something similar where the directory is
@@ -51,6 +55,31 @@ currently in and run `comitium add` for each of them.
 [man]: comitium.1.scd
 
 
+### customizing header
+
+You can customize the header of your feed.gmi.  Simply create a file called
+`header.gmi` in your data directory (where your `comitium.json`, `feed.gmi`, and
+`subscriptions.gmi` are) and put whatever you want in it.  The line linking to
+`subscriptions.gmi` and listing the number of subscriptions will be placed after
+the contents of `header.gmi`, separated by one newline.
+
+For example, if `header.gmi` contains:
+
+```
+# my aggregator
+```
+
+then the final `feed.gmi` will contain:
+
+```
+# my aggregator
+
+=> subscriptions.gmi Currently aggregating X capsules, gopherholes, and websites.
+
+Generated on ...
+```
+
+
 ### refreshing regularly
 
 I just put it in my crontab to refresh on a six hour interval:
@@ -62,9 +91,9 @@ If you set the data directory with an environment variable like mentioned
 earlier, make sure to do something like this, because the environment variable
 isn't passed to cron:
 ```
-0 */6 * * * /usr/local/bin/comitium refresh -d /home/somebody/public_gemini
+0 */6 * * * /home/somebody/bin/comitium refresh -d /home/somebody/public_gemini
 ```
 
 
-And there you go!  You're all set up, now just browse to `feeds.gmi` and get to
-browsin'!
+And there you go!  You're all set up, now just open up your favorite Gemini
+browser, navigate to `feeds.gmi`, and get to surfin'!