Update the minimum supported nodejs version to v10 and fix bugs

[rxliuli]

Note: May contain some bugs, mainly due to two reasons

1. replacing replaceAll with replace
2. replace ? for ||

There are also some non-dangerous replacements
For example, appending the fs-extra module to Promise fs-related operations

---

I created this PR to illustrate how easy it is to support nodejs10. I simply modified a few files. may cause some errors, but I have used this version to generate personal project documents, and it seems that there is no problem at the moment: https://util.liuli.moe/

ref: #20

[rxliuli]

May need a better way to replace replaceAll, as for ??, may need a utility function?

[pklaschka]

First of all: Thank you very much for your contribution. I'll review this asap.

I believe that the replacement for replaceAll works alright since, by using a /g RegEx pattern (at least from the top of my head, I believe it to be that way) replaces all occurrences, anyway.

With ??, I'll have to review the occurrences and look into whether falsy values other than undefined or null are possible in the review process.

[pklaschka]

Alright. Results from my initial review (I'll "GitHub-Review" when I've had the chance to test this more thoroughly, this is just the state of my review, as of now 🙂):

• the ?. in the templates (variable.eta, line 14) also won't work in older versions
• || instead of ?? in templates causes no problems, according to my initial tests. Falsy literal values, such as '' actually result in "''", making it no empty string and, thus, not falsy.
• the package-lock.json is out of date. @rxliuli Please run npm install to bring it up to date with the changes in package.json

[codeclimate]

Code Climate has analyzed commit e9dd5ba and detected 0 issues on this pull request.

View more on Code Climate.

[rxliuli]

Alright. Results from my initial review (I'll "GitHub-Review" when I've had the chance to test this more thoroughly, this is just the state of my review, as of now 🙂):

• the ?. in the templates (variable.eta, line 14) also won't work in older versions
• || instead of ?? in templates causes no problems, according to my initial tests. Falsy literal values, such as '' actually result in "''", making it no empty string and, thus, not falsy.
• the package-lock.json is out of date. @rxliuli Please run npm install to bring it up to date with the changes in package.json

It has been modified. In addition, I merged the upstream modification (ie the latest commit of this repository) and resolved the conflict.

[fussel178]

LGTM. Thank you for your contribution! 😄

[pklaschka]

LGTM, I'll go ahead and merge it 🙂

Thank you very much for your contribution.