update docs

docs/20_Configuration.md

@@ -29,6 +29,9 @@ variable expansion.
 | CM_certmatch       | regex  | matcher to identify domains with dns access; all other domains will use dns alias mode | "\.example\.com" |
 | CM_challenge_alias | string | domain for validation with dns alias mode                  | "example.com" |
 | CM_user            | string | force a user to execute cm.sh                              | default: none (=any user can run cm.sh) |
+| CM_showdebug       | 0\|1   | flag: show debug infos on console (STDOUT)                 | default: 0 |
+| CM_writelog        | 0\|1   | flag: write a log for created/ renewd/ deleted certs       | default: 1 |
+| CM_writedebuglog   | 0\|1   | flag: write a log for executed functions with timer and process count | default: 0 | 
 
 ## inc_config.sh.dist
 
@@ -84,5 +87,17 @@ export ACME=../acme.sh/acme.sh
 # like Ansible or puppet; default: none (=any user can run cm.sh)
 # export CM_user="ansible"
 
+# flag: show debug infos on console (STDOUT)
+# default: 0
+export CM_showdebug=1
+
+# flag: write a log for created/ renewd/ deleted certs
+# default: 1
+# export CM_writelog=1
+
+# flag: write a log for executed functions with timer and process count
+# default: 0
+# export CM_writedebuglog=0
+
 # ----------------------------------------------------------------------
 ```