Update TZUpdater readme.
(https://www.oracle.com/java/technologies/javase/tzupdater-readme.html)

We need to add below entries under 'Tool Updates'

2.3.3 Bug Fix
JDK-8339645: (tzupdater) Improve parsing of Day/Month in tzdata rules
JDK-8340873: (tzupdater) Acknowledge case insensitive unambiguous keywords in tzdata files

Also below section needs to be removed from 'Known Issues'
Entire section under 'tzdata2024b' AND '2020Aa'

The following is a known issue when processing tzdata2024b:

The 2024b update has a change that uses "April" instead of the abbreviation ("Apr"), which causes the TZUpdater tool to fail in its month-parsing logic.

The issue is being tracked under:

https://bugs.openjdk.org/browse/JDK-8339645

Perform the following workaround to address this issue:

Download the tzdata2024b bundle from the following location:
https://data.iana.org/time-zones/releases/tzdata2024b.tar.gz
Extract the contents of tzdata2024b.tar.gz to a local directory.
Open the northamerica file in a text editor and modify the rule entry on line number 2634 in the IN column from April to Apr as specified in the following patch in IANA:
https://github.com/eggert/tz/commit/926b507fa5c3192b1b68fab5910cbd3ba9377c97

Compress and package the modified tzdata2024b bundle. For example, the following command compresses and packages the modified bundle in a file named tzdata_modified.tar.gz:

tar -czvf <directory in which to create the modified bundle>/tzdata_modified.tar.gz *
Run the TZUpdater tool and specify the modified bundle path in the -l option. For example:
java -jar tzupdater.jar -l file://&lt;directory that contains the modified bundle>/tzdata_modified.tar.gz

tzdata2020a
The following is a known issue when processing tzdata2020a:

Due to formatting changes in the IANA-maintained tzdata bundle, the TZUpdater tool fails to update to tzdata2020a for JDK 7u.

The issue is being tracked under:

https://bugs.openjdk.java.net/browse/JDK-8245950

Please refer to the bug for a temporary workaround.