float: add page (#21168)

* float: add page

* Update pages/common/float.md

Co-authored-by: Harshavardhan <harshath3018@gmail.com>

* remove invalid `-E` flag example

---------

Co-authored-by: Ivan Baluta <ivanbaluta.dev@gmail.com>
Co-authored-by: Harshavardhan <harshath3018@gmail.com>

pages/common/float.md

@@ -0,0 +1,22 @@
+# float
+
+> Declare floating point variable(s).
+> Equivalent to `typeset -E` except that options irrelevant to floating point numbers are not permitted.
+> See also: `typeset`, `declare`.
+> More information: <https://manned.org/zshbuiltins>.
+
+- Declare a floating point variable:
+
+`float {{variable_name}}`
+
+- Declare a floating point variable while assigning its value:
+
+`float {{variable_name}}={{value}}`
+
+- Declare multiple floating point variables:
+
+`float {{var1=value1 var2=value2 ...}}`
+
+- Display defined variables:
+
+`float`