Update docker.md (#2253)

The space separator between the key and the value has been deprecated; instead, use the format "ENV key=value"

docusaurus/docs/dev-docs/installation/docker.md

@@ -71,7 +71,7 @@ WORKDIR /opt/
 COPY package.json yarn.lock ./
 RUN yarn global add node-gyp
 RUN yarn config set network-timeout 600000 -g && yarn install
-ENV PATH /opt/node_modules/.bin:$PATH
+ENV PATH=/opt/node_modules/.bin:$PATH
 
 WORKDIR /opt/app
 COPY . .
@@ -97,7 +97,7 @@ WORKDIR /opt/
 COPY package.json package-lock.json ./
 RUN npm install -g node-gyp
 RUN npm config set fetch-retry-maxtimeout 600000 -g && npm install
-ENV PATH /opt/node_modules/.bin:$PATH
+ENV PATH=/opt/node_modules/.bin:$PATH
 
 WORKDIR /opt/app
 COPY . .
@@ -352,7 +352,7 @@ WORKDIR /opt/
 COPY package.json yarn.lock ./
 RUN yarn global add node-gyp
 RUN yarn config set network-timeout 600000 -g && yarn install --production
-ENV PATH /opt/node_modules/.bin:$PATH
+ENV PATH=/opt/node_modules/.bin:$PATH
 WORKDIR /opt/app
 COPY . .
 RUN yarn build
@@ -366,7 +366,7 @@ WORKDIR /opt/
 COPY --from=build /opt/node_modules ./node_modules
 WORKDIR /opt/app
 COPY --from=build /opt/app ./
-ENV PATH /opt/node_modules/.bin:$PATH
+ENV PATH=/opt/node_modules/.bin:$PATH
 
 RUN chown -R node:node /opt/app
 USER node
@@ -389,7 +389,7 @@ WORKDIR /opt/
 COPY package.json package-lock.json ./
 RUN npm install -g node-gyp
 RUN npm config set fetch-retry-maxtimeout 600000 -g && npm install --only=production
-ENV PATH /opt/node_modules/.bin:$PATH
+ENV PATH=/opt/node_modules/.bin:$PATH
 WORKDIR /opt/app
 COPY . .
 RUN npm run build
@@ -403,7 +403,7 @@ WORKDIR /opt/
 COPY --from=build /opt/node_modules ./node_modules
 WORKDIR /opt/app
 COPY --from=build /opt/app ./
-ENV PATH /opt/node_modules/.bin:$PATH
+ENV PATH=/opt/node_modules/.bin:$PATH
 
 RUN chown -R node:node /opt/app
 USER node