add doc

README.md

@@ -591,6 +591,7 @@ List of all available rules. The rules ported from `golint` are left unchanged a
 | [`unexported-naming`](./RULES_DESCRIPTIONS.md#unexported-naming)          |  n/a   |  Warns on wrongly named un-exported symbols       |    no    |  no   |
 | [`unexported-return`](./RULES_DESCRIPTIONS.md#unexported-return)   |  n/a   | Warns when a public return is from unexported type.              |   yes    |  yes  |
 | [`unhandled-error`](./RULES_DESCRIPTIONS.md#unhandled-error)   | []string   | Warns on unhandled errors returned by function calls    |    no    |  yes   |
+| [`unnecessary-conditional`](./RULES_DESCRIPTIONS.md#unnecessary-conditional)    |  n/a   | Identifies `if-else` statements that can be replaced by simpler statements  |    no    |  no   |
 | [`unnecessary-format`](./RULES_DESCRIPTIONS.md#unnecessary-format)    |  n/a   | Identifies calls to formatting functions where the format string does not contain any formatting verbs          |    no    |  no   |
 | [`unnecessary-stmt`](./RULES_DESCRIPTIONS.md#unnecessary-stmt)    |  n/a   | Suggests removing or simplifying unnecessary statements          |    no    |  no   |
 | [`unreachable-code`](./RULES_DESCRIPTIONS.md#unreachable-code)    |  n/a   | Warns on unreachable code                                        |    no    |  no   |

RULES_DESCRIPTIONS.md

@@ -87,6 +87,7 @@ List of all available rules.
 - [unexported-naming](#unexported-naming)
 - [unexported-return](#unexported-return)
 - [unhandled-error](#unhandled-error)
+- [unnecessary-conditional](#unnecessary-conditional)
 - [unnecessary-format](#unnecessary-format)
 - [unnecessary-stmt](#unnecessary-stmt)
 - [unreachable-code](#unreachable-code)
@@ -1499,6 +1500,39 @@ arguments = [
 ]
 ```
 
+## unnecessary-conditional
+
+_Description_: Detects unnecessary `if-else` statements that return or assign a boolean value
+based on a condition and suggests a simplified, direct return or assignment.
+The `if-else` block is redundant because the condition itself is already a boolean expression.
+The simplified version is immediately clearer, more idiomatic, and reduces cognitive load for the reader.
+
+### Examples (unnecessary-conditional)
+
+```go
+if y <= 0 {
+  z = true
+} else {
+  z = false
+}
+
+if x > 10 {
+  return false
+} else {
+  return true
+}
+```
+
+Fixed code:
+
+```go
+z = y <= 0
+
+return x <= 10
+```
+
+_Configuration_: N/A
+
 ## unnecessary-format
 
 _Description_: This rule identifies calls to formatting functions where the format string does not contain any formatting verbs