Use diffprereqs files as dependencies, not FORCE

[Shushe] / README.markdown

diff --git a/README.markdown b/README.markdown
index 8ae0a04f5bad55f6d2ca8d604ca5ac1594d6c6bd..503a16338dda83163e59c655e8c9a02cf00d66ec 100644 (file)
--- a/README.markdown
+++ b/README.markdown
@@ -244,6 +244,14 @@ The following additional variables can be used to control the behaviour
   Multiple include directories can be provided, so long as the same
     file subpath doesn’t exist in more than one of them.
 
+- **`DATADIR`:**
+  If set to the location of a directory, ⛩📰 书社 will run a two‐stage build.
+  In the first stage, only files in `SRCDIR` which match `FINDDATARULES` (see below) will be built, with files in `DATADIR` serving as includes.
+  In the second stage, the remaining files in `SRCDIR` will be built, with the files built during the first stage, in addition to any files in `INCLUDEDIR`, serving as includes.
+  Files built during the first stage are copied into `DESTDIR` alongside those from the second stage when installing.
+
+  This functionality is intended for sites where the bulk of the site can be built from a few data files which are expensive to create.
+
 - **`BUILDDIR`:**
   The location of the (temporary) build directory (default: `build`).
   `make clean` will delete this, and it is recommended that it not be
@@ -299,6 +307,18 @@ The following additional variables can be used to control the behaviour
     default, to enable additional rules without overriding the existing
     ones.
 
+- **`DATAEXT`:**
+  A list of file extensions which signify “data” files during a two‐stage build using `DATADIR`.
+
+- **`FINDDATARULES`:**
+  Rules to use with `find` when searching for data files.
+  By default, these rules are derived from `DATAEXT`.
+
+- **`EXTRAFINDDATARULES`:**
+  The value of this variable is appended to `FINDDATARULES` by
+    default, to enable additional rules without overriding the existing
+    ones.
+
 - **`PARSERS`:**
   A white·space‐separated list of parsers to use (default:
     `$(THISDIR)/parsers/*.xslt`).