README.md in rdoc_link_checker-0.2.0 vs README.md in rdoc_link_checker-0.3.0

@@ -1,6 +1,35 @@
 # RDoc Link Checker
 
-Not ready for prime time.  Just wanted to reserve the name.
+A gem to find broken links in HTML files generated by Ruby RDoc.
 
-Development is active,
-so should be up in a few days (say, by the end of May 2023).
+Reports a link as broken if:
+
+- The target page given by +href+ is not found.
+- The target page is found, but the fragment given by +href+
+  is not a link target on that page;
+  this usually causes a browser to open at the top of the page
+  instead of at the given fragment.
+
+Note that some browsers are forgiving, and will open the target
+page at a link target similar to the given fragment;
+for example, fragment ```bar``` may be opened at an element
+with id ```foobar```.
+
+```
+Usage:
+rdoc_link_checker html_dirpath options
+
+The argument is the path to a directory containing a tree
+of RDoc-generated HTML files, such as those generated by command
+
+rdoc --visibility=private --op html . # Note the trailing dot.
+
+Options:
+--onsite_only   Check link targets only on pages in the file tree at <html_dirpath>,
+                and not those on other local pages or those on the web.
+--no_toc        Do not check links on the TOC page (table_of_contents.html).
+--version       Print the version and exit.
+--help          Print this help and exit.
+
+The output is file <html_dirpath>/Report.htm, which reports broken links.
+```