[dv, doc] doc for dv_lib, plus some fixes

- added README for dv_lib (WIP)
- some basic fixes
- fixes to support moving DV plan document to ip/*/doc and testplan
Hjson to ip/*/data
diff --git a/util/uvmdvgen/env_cov.sv.tpl b/util/uvmdvgen/env_cov.sv.tpl
index c07b312..18cd77c 100644
--- a/util/uvmdvgen/env_cov.sv.tpl
+++ b/util/uvmdvgen/env_cov.sv.tpl
@@ -2,6 +2,12 @@
 // Licensed under the Apache License, Version 2.0, see LICENSE for details.
 // SPDX-License-Identifier: Apache-2.0
 
+/**
+ * Covergoups that are dependent on run-time parameters that may be available
+ * only in build_phase can be defined here
+ * Covergroups may also be wrapped inside helper classes if needed.
+ */
+
 % if is_cip:
 class ${name}_env_cov extends cip_base_env_cov #(.CFG_T(${name}_env_cfg));
 % else:
@@ -13,10 +19,20 @@
   // ${name}_env_cfg: cfg
 
   // covergroups
+  // [add covergroups here]
 
   function new(string name, uvm_component parent);
     super.new(name, parent);
-    // instantiate all covergroups here
+    // [instantiate covergroups here]
   endfunction : new
 
+  virtual function void build_phase(uvm_phase phase);
+    super.build_phase(phase);
+    // [or instantiate covergroups here]
+% if is_cip:
+    // Please instantiate sticky_intr_cov array of objects for all interrupts that are sticky
+    // See cip_base_env_cov for details
+% endif
+  endfunction
+
 endclass