bugs in gen_installer.sh

[larvata]

Some bugs prevent the script from working correctly when the user specifies arguments.

1. Wrong usage example in doc:

docker run -v $(pwd):/root/workspace tdmelodic:latest \
    bash /tmp/script/gen_installer.sh \
    --neologd=${NEOLOGD_SRC_DIR} \
    --unidic=${UNIDIC_ZIP} \
    --dictionary=${TDMELODIC_CSV}

->

docker run -v $(pwd):/root/workspace tdmelodic:latest \
    bash /tmp/script/gen_installer.sh \
    --neologd ${NEOLOGD_SRC_DIR} \
    --unidic ${UNIDIC_ZIP} \
    --dictionary ${TDMELODIC_CSV}

2. The $YMD is incorrect when the user specifies the $NEOLOGD_DIR
   $YMD should be generated after the user-specified arguments are handled.

3. The option "--ymd" does not work, this argument shouldn't be processed with "readlink"

4. The script "script/gen_installer.sh" doesn't have the execution permission, in my experience, it is safe to set the execution permission in the repository.

[tachi-hi]

Thank you! I'll check that.

[tachi-hi]

(#16)

• I wrote an instruction to install tdmelodic using the unidic_kana-accent installation script instead of that of neologd.
• I removed gen_installer.sh. It is messy, and not a very good installation script.