updated remaining WRAP blocks with Mkdocs Admonitions

docs/commands/builtin/let.md

@@ -41,12 +41,13 @@ command](../../syntax/ccmd/arithmetic_eval.md):
     $ echo "$a - $b - $?"
     4 - 2 - 0
 
-<WRAP info> Remember that inside arithmetic evaluation contexts, all
-other expansions are processed as usual (from left-to-right), and the
-resulting text is evaluated as an arithmetic expression. Arithmetic
-already has a way to control precedence using parentheses, so it's very
-rare to need to nest arithmetic expansions within one another. It's
-used above only to illustrate how this precedence works. </WRAP>
+!!! INFO ""
+    Remember that inside arithmetic evaluation contexts, all
+    other expansions are processed as usual (from left-to-right), and the
+    resulting text is evaluated as an arithmetic expression. Arithmetic
+    already has a way to control precedence using parentheses, so it's very
+    rare to need to nest arithmetic expansions within one another. It's
+    used above only to illustrate how this precedence works.
 
 Unlike `((`, being a simple command `let` has its own environment. In
 Bash, built-ins that can set variables process any arithmetic under

docs/commands/builtin/read.md

@@ -20,18 +20,17 @@ If `<NAME...>` is given, the line is word-split using
 `<NAME>`. The remaining words are all assigned to the last `<NAME>` if
 more words than variable names are present.
 
-<WRAP center round info 90%> If no `<NAME>` is given, the whole line
-read (without performing word-splitting!) is assigned to the shell
-variable [REPLY](../../syntax/shellvars.md#REPLY). Then, `REPLY` really contains
-the line as it was read, without stripping pre- and postfix spaces and
-other things!
+!!! INFO
+    If no `<NAME>` is given, the whole line
+    read (without performing word-splitting!) is assigned to the shell
+    variable [REPLY](../../syntax/shellvars.md#REPLY). Then, `REPLY` really contains
+    the line as it was read, without stripping pre- and postfix spaces and
+    other things!
 
         while read -r; do
           printf '"%s"\n' "$REPLY"
         done <<<"  a line with prefix and postfix space  "
 
-</WRAP>
-
 If a timeout is given, or if the shell variable
 [TMOUT](../../syntax/shellvars.md#TMOUT) is set, it is counted from initially
 waiting for input until the completion of input (i.e. until the complete

docs/howto/mutex.md

@@ -61,8 +61,9 @@ they are succesfully locked, and can operate without colliding. Setting
 the timestamp is similar: One step to check the timespamp, a second step
 to set the timestamp.
 
-<WRAP center round tip 60%> <u>**Conclusion:**</u> We need an
-operation that does the check and the locking in one step. </WRAP>
+!!! NOTE ""
+    <u>**Conclusion:**</u> We need an
+    operation that does the check and the locking in one step.
 
 A simple way to get that is to create a **lock directory** - with the
 mkdir command. It will: