make it a whole lot easier to set custom env variables

.env.example

@@ -0,0 +1,19 @@
+# these are the defaults -- to override any of them, simply add a line to a new
+# file named '.env'. (this new file should only contain the variables you wish
+# to override; the rest should be left alone.)
+
+# name of the non-root user running mastodon
+MASTODON_USER=mastodon
+
+# default paths
+MASTODON_ROOT="/home/$MASTODON_USER"  # absolute path to home dir of above user
+UTILS_ROOT="$MASTODON_ROOT/utils"     # this repository
+APP_ROOT="$MASTODON_ROOT/live"        # Mastodon source
+BACKUPS_ROOT="$MASTODON_ROOT/backups" # backups destination
+LOGS_ROOT="$MASTODON_ROOT/logs"       # logs destination
+
+# paths to rbenv and nvm installations (both are automatically installed by
+# install.sh to these default directories, but the specific environment
+# variables are still required)
+RBENV_ROOT="$MASTODON_ROOT/.rbenv"    # rbenv (w/ ruby-build plugin) directory
+NVM_DIR="$MASTODON_ROOT/.nvm"         # nvm directory