add docs

taskfile/ast/precondition.go

@@ -4,12 +4,10 @@ import (
 	"fmt"
 	"sync"
 
-
+	"github.com/go-task/task/v3/errors"
 	"github.com/go-task/task/v3/internal/deepcopy"
 
 	"gopkg.in/yaml.v3"
-
-	"github.com/go-task/task/v3/errors"
 )
 
 // Precondition represents a precondition necessary for a task to run
@@ -25,6 +23,12 @@ type (
 	}
 )
 
+func NewPreconditions() *Preconditions {
+	return &Preconditions{
+		Preconditions: make([]*Precondition, 0),
+	}
+}
+
 func (p *Preconditions) DeepCopy() *Preconditions {
 	if p == nil {
 		return nil
@@ -46,12 +50,6 @@ func (p *Precondition) DeepCopy() *Precondition {
 	}
 }
 
-func NewPreconditions() *Preconditions {
-	return &Preconditions{
-		Preconditions: make([]*Precondition, 0),
-	}
-}
-
 // UnmarshalYAML implements yaml.Unmarshaler interface.
 func (p *Precondition) UnmarshalYAML(node *yaml.Node) error {
 	switch node.Kind {

website/docs/usage.mdx

@@ -1019,6 +1019,21 @@ tasks:
       - echo "I will not run"
 ```
 
+They can be defined at two levels:
+
+- Global Level: Applies to all tasks.
+- Task Level: Applies only to a specific task.
+
+```yaml
+version: '3'
+
+preconditions:
+  - sh: 'exit 1'
+
+tasks:
+  task-will-fail: echo "I will not run"
+```
+
 ### Limiting when tasks run
 
 If a task executed by multiple `cmds` or multiple `deps` you can control when it