Tests: Add test descriptions

t/00-build-artifacts.test

@@ -1,4 +1,9 @@
 #! /bin/bash
+cat <<---
+This test checks that the built Nginx either has the dynamic fancyindex
+module available, or that it's not there (for static builds).
+--
+
 readonly nginx_path="${PREFIX}/sbin/nginx"
 readonly so_path="${PREFIX}/modules/ngx_http_fancyindex_module.so"
 

t/01-smoke-hasindex.test

@@ -1,3 +1,7 @@
 #! /bin/bash
+cat <<---
+This test fetches the root directory served by Nginx, which has no index file,
+and checks that the output contains something that resembles a directory index.
+--
 nginx_start
 grep 'Index of' <( fetch )

t/02-smoke-indexisfancy.test

@@ -1,4 +1,9 @@
 #! /bin/bash
+cat <<---
+This test fetches the root directory served by Nginx, which has no index file,
+and checks that the output contains something that resembles the output from
+the fancyindex module.
+--
 nginx_start
 content=$(fetch --with-headers)
 grep 'Index of /' <<< "${content}"  # It is an index