Create and document basic installation script

README.md

@@ -4,6 +4,35 @@ would-reformat - automatic reformatting for emacs without being annoying
 
 # Installation
 
+- Change to the directory where you would want to use **would-reformat**:
+  `$ cd ~/devel/my-project`
+- From that directory, call the script `install.sh` in the directory where
+  you have **would-reformat** checked out:
+  `you@host:~/devel/my-project $ ~/src/would-reformat/install.sh`
+
+This will do the following:
+
+- create the directory `~/devel/my-project/bin` if it does not exist
+- create `~/devel/my-project/_reformat-common.sh`,
+  `~/devel/my-project/do-reformat.sh`, and
+  `~/devel/my-project/bin/would-reformat.sh` as symlinks to files with
+  the same names in `~/src/would-reformat`.
+- create `~/devel/my-project/.dir-locals.el` as a symlink to the file
+  with the same name in `~/src/would-reformat`.
+
+This should work from a checkout wherever you happen to have it.  It doesn't
+need to be in `~/src`.  However, if you remove the checkout, then the symlinks
+will break, so don't do that.  If you rename the checkout, the symlinks will break.
+
+The directory `bin` with respect to `my-project` however is hardcoded
+(enhancements here are welcome).
+
+The script `install.sh` favors conservatism over being clever: for example,
+if it finds the file `~/devel/my-project/bin/do-reformat.sh` then it
+checks whether it is a symlink to `~/src/would-reformat/do-reformat.sh`.
+If it is not, then it just prints a warning rather than attempting to correct
+the situation.
+
 # Development