document updated for filter and until options

examples of image prune with filter and until options added

Signed-off-by: Kunal Kushwaha <kunal.kushwaha@gmail.com>

docs/source/markdown/podman-image-prune.1.md

@@ -25,13 +25,16 @@ Print usage statement
 Remove all dangling images from local storage
 ```
 $ sudo podman image prune
+
+WARNING! This will remove all dangling images.
+Are you sure you want to continue? [y/N] y
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 ```
 
-Remove all unused images from local storage
+Remove all unused images from local storage without confirming
 ```
-$ sudo podman image prune -a
+$ sudo podman image prune -a -f
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@@ -41,6 +44,40 @@ e4e5109420323221f170627c138817770fb64832da7d8fe2babd863148287fca
 
 ```
 
+Remove all unused images from local storage since given time/hours.
+```
+$ sudo podman image prune -a --filter until=2019-11-14T06:15:42.937792374Z
+
+WARNING! This will remove all dangling images.
+Are you sure you want to continue? [y/N] y
+e813d2135f17fadeffeea8159a34cfdd4c30b98d8111364b913a91fd930643e9
+5e6572320437022e2746467ddf5b3561bf06e099e8e6361df27e0b2a7ed0b17b
+58fda2abf5042b35dfe04e5f8ee458a3cc26375bf309efb42c078b551a2055c7
+6d2bd30fe924d3414b64bd3920760617e6ced872364bc3bc6959a623252da002
+33d1c829be64a1e1d379caf4feec1f05a892c3ef7aa82c0be53d3c08a96c59c5
+f9f0a8a58c9e02a2b3250b88cc5c95b1e10245ca2c4161d19376580aaa90f55c
+1ef14d5ede80db78978b25ad677fd3e897a578c3af614e1fda608d40c8809707
+45e1482040e441a521953a6da2eca9bafc769e15667a07c23720d6e0cafc3ab2
+
+$ sudo podman image prune -f --filter until=10h
+f3e20dc537fb04cb51672a5cb6fdf2292e61d411315549391a0d1f64e4e3097e
+324a7a3b2e0135f4226ffdd473e4099fd9e477a74230cdc35de69e84c0f9d907
+```
+
+Remove all unused images from local storage with label version 1.0
+```
+$ sudo podman image prune -a -f --filter label=version=1.0
+e813d2135f17fadeffeea8159a34cfdd4c30b98d8111364b913a91fd930643e9
+5e6572320437022e2746467ddf5b3561bf06e099e8e6361df27e0b2a7ed0b17b
+58fda2abf5042b35dfe04e5f8ee458a3cc26375bf309efb42c078b551a2055c7
+6d2bd30fe924d3414b64bd3920760617e6ced872364bc3bc6959a623252da002
+33d1c829be64a1e1d379caf4feec1f05a892c3ef7aa82c0be53d3c08a96c59c5
+f9f0a8a58c9e02a2b3250b88cc5c95b1e10245ca2c4161d19376580aaa90f55c
+1ef14d5ede80db78978b25ad677fd3e897a578c3af614e1fda608d40c8809707
+45e1482040e441a521953a6da2eca9bafc769e15667a07c23720d6e0cafc3ab2
+
+```
+
 ## SEE ALSO
 podman(1), podman-images