feature update

[tand826]

• warn if the uploaded csv does not have the required columns (fileReader.onload())
• update years in datacheck()
• enable trash icon to delete the registered csv data (trashIcon)

[tand826]

• Event.initEvent() is deprecated. see MDN

[tand826]

all search words should be in lower case

[tand826]

• update years : https://github.com/tand826/pubmed_impact_factor_search/commit/814bf7d2838c34fd8015d7517cee6070ab6b2d05, https://github.com/tand826/pubmed_impact_factor_search/commit/3787da60138b363a99127ddd07836dde15153d05
• warn unexpected format: https://github.com/tand826/pubmed_impact_factor_search/commit/2cafc1bb12299599667f94eff6ca9944cc816806
• enable trash: https://github.com/tand826/pubmed_impact_factor_search/commit/c8b06457a3fca5d1f37502039ef8c024592f0357
• search words in lower case: https://github.com/tand826/pubmed_impact_factor_search/commit/800fd930dd76d1f446c671daf5a12415b8038f7a
• initEvent(): https://github.com/tand826/pubmed_impact_factor_search/commit/4be43d2afbcc9b65cf02577119dd0778c0d0257a