Adding changelog entries (#266)

.changes/unreleased/FEATURES-20240111-142126.yaml

@@ -0,0 +1,6 @@
+kind: FEATURES
+body: 'statecheck: Introduced new `statecheck` package with interface and built-in
+  state check functionality'
+time: 2024-01-11T14:21:26.261094Z
+custom:
+  Issue: "273"

.changes/unreleased/FEATURES-20240111-142223.yaml

@@ -0,0 +1,6 @@
+kind: FEATURES
+body: 'statecheck: Added `ExpectKnownValue` state check, which asserts that a given
+  resource attribute has a defined type, and value'
+time: 2024-01-11T14:22:23.072321Z
+custom:
+  Issue: "273"

.changes/unreleased/FEATURES-20240111-142314.yaml

@@ -0,0 +1,6 @@
+kind: FEATURES
+body: 'statecheck: Added `ExpectKnownOutputValue` state check, which asserts that
+  a given output value has a defined type, and value'
+time: 2024-01-11T14:23:14.025585Z
+custom:
+  Issue: "273"

.changes/unreleased/FEATURES-20240111-142353.yaml

@@ -0,0 +1,6 @@
+kind: FEATURES
+body: 'statecheck: Added `ExpectKnownOutputValueAtPath` plan check, which asserts
+  that a given output value at a specified path has a defined type, and value'
+time: 2024-01-11T14:23:53.633255Z
+custom:
+  Issue: "273"

.changes/unreleased/FEATURES-20240111-142544.yaml

@@ -0,0 +1,6 @@
+kind: FEATURES
+body: 'statecheck: Added `ExpectSensitiveValue` built-in state check, which asserts
+  that a given attribute has a sensitive value'
+time: 2024-01-11T14:25:44.598583Z
+custom:
+  Issue: "273"