EDF entries: specify default values

Author: gwangmu

docs/software/container-engine/edf.md

@@ -5,11 +5,10 @@ EDF files use the [TOML format](https://toml.io/en/). For details about the data
 
 ## EDF entries 
 
-If not specified, the default value is an empty value of the corresponding type.
-
 ### `base_environment`
 
  * Type: array or string
+ * Default: `""`
 
 Ordered list of EDFs that this file inherits from. Parameters from listed environments are evaluated sequentially. Supports up to 10 levels of recursion.
 
@@ -32,6 +31,7 @@ Ordered list of EDFs that this file inherits from. Parameters from listed enviro
 ### `image`
 
  * Type: string
+ * Default: **(mandatory)**
 
 The container image to use. Can reference a remote Docker/OCI registry or a local Squashfs file as a filesystem path.
 
@@ -71,7 +71,7 @@ The container image to use. Can reference a remote Docker/OCI registry or a loca
 ### `workdir`
 
  * Type: string
- * Default: inherited from image
+ * Default: (inherited from image)
 
 Initial working directory when the container starts.
 
@@ -100,7 +100,7 @@ If true, run the entrypoint from the container image.
 ### `writable`
 
  * Type: bool
- * Type: `true`
+ * Default: `true`
 
 If false, the container filesystem is read-only.
 
@@ -112,6 +112,7 @@ If false, the container filesystem is read-only.
 ### `mounts`
 
  * Type: array
+ * Default: `[]`
 
 List of bind mounts in the format `SOURCE:DESTINATION[:FLAGS]`. Flags are optional and can include `ro`, `private`, etc.
 
@@ -139,7 +140,7 @@ List of bind mounts in the format `SOURCE:DESTINATION[:FLAGS]`. Flags are option
 
 ### `env`
 
- * Default: inherited from the host and the image
+ * Default: (inherited from the host and the image)
 
 Environment variables to set in the container. Empty string values will unset the variable.
 
@@ -166,6 +167,8 @@ Environment variables to set in the container. Empty string values will unset th
 
 ### `annotations`
 
+ * Default: (none)
+
 OCI-like annotations for the container. For more details, refer to the [Annotations][ref-ce-annotations] section.
 
 !!! example